Logo

The OEIS Foundation Inc.

Other ways to Give

This is the Home Page for The OEIS Foundation Inc.

Jan. 2015: John Riordan Prize of $1000 for the best solution to an open problem in the OEIS.

Dec. 2014: There is a new OEIS poster and key, to celebrate 250,000 sequences

Press release, September 23 2014:   The OEIS: 50 years of identifying number sequences

Goals of The OEIS Foundation Inc.

The OEIS Foundation Inc. is a New Jersey nonprofit corporation (#0101000611; Articles of incorporation filed with the State of New Jersey, April 14 2009; EIN 30-0562250) whose main goals are the following four items:

  1. To own the intellectual property known as "The On-Line Encyclopedia of Integer Sequences®" (or "OEIS®").
  2. To maintain the OEIS as a service that is freely accessible by the general public.
  3. To act so as to maintain its own existence indefinitely.
  4. To collect and distribute funds in order to carry out the first three goals.

These goals are described in greater detail in a later section of this web page, and in the Articles of Incorporation and Bylaws.

To facilitate the fourth goal, The OEIS Foundation Inc. has been approved by the Internal Revenue Service as a charity and a Section 501(c)(3) tax-exempt organization. For details please see the section on Tax-exempt status. Tax-deductible donations to The OEIS Foundation Inc. can be made through PayPal using the icon at the top right of this page (see also below).

Note: Except when used in the name of this corporation (The OEIS Foundation Inc.), the word "OEIS" is an abbreviation for "The On-Line Encyclopedia of Integer Sequences®".

Description of The On-Line Encyclopedia of Integer Sequences® (or OEIS®)

The On-Line Encyclopedia of Integer Sequences® (OEIS®) is the on-line version of a database of sequences of numbers which will soon be celebrating its 50th anniversary.

A conventional dictionary is a collection of words, together with explanations of their meanings, hints for their pronunciation, pictures illustrating particular words, examples showing how the words have been used in books and newspapers, and so on.

The OEIS is a collection of sequences of numbers (such as 1, 2, 4, 8, 16, 32, 64, 128, ...) together with, for each sequence, a list of items such as:

  • The first 10, or 10,000, or sometimes 500,000 terms of the sequence
  • A definition or description of the sequence
  • Comments explaining further properties of the sequence
  • Formulas for generating the sequence
  • Computer programs for generating the sequence
  • References to books and articles where the sequence has appeared
  • Links to web pages on the Internet where the sequence has appeared
  • Cross-references to related entries in the OEIS
  • The name of the person who submitted the sequence to the OEIS
  • Further names of people who have added additional information about the sequence
  • Examples illustrating some of the terms of the sequence (for example, sequence A124. which gives the maximal number of pieces that can be obtained when cutting a circular pancake with n cuts, is illustrated with pictures showing the pieces obtained with n = 1, 2, 3, 4 and 5 cuts)
  • The history of each sequence in the OEIS as it has evolved over time
  • Users of the OEIS may also view graphs or plots of each sequence, or to listen to the sequence when it is converted to music

The OEIS currently contains just over 200,000 entries. These have been distilled from many sources - books, journals, articles, and letters and electronic mail messages from thousands of contributors. Since November 11, 2010, users have been able to enter contributions directly into the OEIS (all such contributions are refereed).

How the OEIS is used

The main use for the OEIS is to identify a number sequence that you have come across, perhaps in your work, while reading a book, or in a quiz, etc.

For example, you discover what you think may be a new algorithm for checking that a file of medical records is in the correct order. (Perhaps you are a computer scientist or someone working in information science.)

To handle files of 1, 2, 3, 4, ... records, your algorithm takes 0, 1, 3, 5, 9, 11, 14, 17, 25, ... steps.

How can you check if someone has discovered this algorithm before? You decide to ask the OEIS if this sequence has appeared before in the scientific literature.

You go the OEIS web site, enter the numbers you have calculated, and click "Submit".

The reply tells you that this is sequence A3071, which is the number of steps needed for "sorting by list merging", a well-known algorithm. The entry directs you to Section 5.3.1 of Volume 3 of D. E. Knuth, "The Art of Computer Programming", where you find your algorithm described. The entry even gives an explicit formula for the nth term. You decide not to apply for a patent!

The OEIS web site includes a list of well over 3000 books and articles that have acknowledged help from the OEIS.

For further information about the OEIS, see the OEIS Welcome Page, the Lookup Page, the Demonstration Pages, or the Wikipedia article.

History of the OEIS

The collection was begun by Neil J. A. Sloane (henceforth, "NJAS") in 1964 when he was a graduate student at Cornell University in Ithaca NY. He had encountered a sequence of numbers while working on his dissertation, namely 1, 8, 78, 944, ... (now entry A435. in the OEIS), and was looking for a formula for the n-th term, in order to determine the rate of growth of the terms.

He noticed that although several books in the Cornell library contained sequences somewhat similar to this, this particular sequence was not mentioned. In order to keep track of the sequences in these books, NJAS started recording them on file cards, which he sorted into lexicographic order.

The sequences were transferred to punched cards in 1967, and were made into a book in 1973 ("A Handbook of Integer Sequences", by NJAS, Academic Press, NY).

NJAS joined AT&T Bell Laboratories in 1969. Following the publication of the book, a large amount of correspondence ensued, with suggestions for further sequences and updates to the existing entries. Many people remarked how useful they found the book, and how surprising it was that no one had published such a collection before.

By the early 1990's over a cubic meter of of correspondence had accumulated. A Canadian mathematician, Simon Plouffe, offered to help in preparing a revised edition of the book, and in 1995 "The Encyclopedia of Integer Sequences", by NJAS and Simon Plouffe, was published by Academic Press, San Diego. (Simon Plouffe is now one of the Trustees of The OEIS Foundation Inc.) The 1973 book contained 2372 sequences, and the 1995 book 5487 sequences, occupying 587 pages.

Again, once the book appeared, many further sequences and updates were submitted from people all over the world. NJAS waited a year, until the size of the collection had doubled, to 10,000 entries, and then in 1996 he launched the On-Line Encyclopedia of Integer Sequences on the Internet. From 1996 until November 11, 2010, this was part of NJAS's home page on the AT&T Labs Web Site.

Since 1996, the collection has grown by 10,000 to 18,000 entries per year. At the present time (May 29, 2013) there are 225,735 entries. If it were to be published in book form today, it would require at least 750 volumes the size of the 1995 book.

Starting in 2002, NJAS added a group of associate editors to help process submissions to the OEIS. However, because they did not have access to the computer where the OEIS was maintained, almost all the work of updating it had to be done single-handedly by NJAS. This involved processing 100 or 200 emails every day, and was getting to be beyond what one person could handle.

In January 2009, therefore, it was decided to make a drastic change. We (NJAS and the associate editors) made a plan to convert the OEIS into a "wiki" format, somewhat along the lines of the well-known Wikipedia, which would be hosted by a commercial hosting service. (A copy of a letter of consent from AT&T agreeing to this course of action is available on request from NJAS.) It was also decided to set up the OEIS Foundation, the goals of which would be to own, maintain and raise funds to support the new version of the OEIS.

Most of this went smoothly. The OEIS Foundation Inc. was incorporated in the State of New Jersey on April 14, 2009. We rented space on a commercial hosting service, and tried to move the OEIS to the new site.

Here, however, we ran into a very serious problem. In the summer of 2009, when we tried to get the OEIS working as a wiki, we discovered that the Mediawiki software was not capable of handling the kind of queries that arise in looking up sequences. This was a disaster.

It took us over a year to resolve this problem. In the end, Russ Cox completely rewrote all the programs needed to maintain the database and answer queries - a huge task! NJAS's colleague David Applegate has also been of enormous help in getting the new system working.

As a result of their work, the new OEIS was finally launched on November 11, 2010. (For more details, see the attached announcement.)

It is now possible for anyone in the world to propose a new sequence or an update to an existing sequence. To do this, users must first register. A group of about 70 editors has been formed, whose job it is to review submissions before they become a permanent part of the OEIS.

So, after nearly two years of struggle, the OEIS can finally operate without NJAS having to approve every change. After 46 years of running the database, this comes as a great relief to him.

The new OEIS

As mentioned in the previous paragraph, the OEIS was successfully launched in its new home (http://oeis.org) on November 11, 2010. At this time it contained 180,284 sequences.

In the first full year of operation, from Nov 11 2010 to Dec 1 2011, 19716 new sequences were accepted, an average of over 50 per day, and there were about 250 edits per day of existing sequences.
We now have over 20 Editors-in-Chief and over 80 Associate Editors, and about 2000 registered users (see here for these lists).

The following is a summary of the traffic on the new web site for the month of December 2010. The first four columns are the daily average, the last six columns are the total for the month.

Hits Files Pages Visits   |   Sites KBytes Visits Pages Files Hits
164491 93721 141310 8290   |   84612 40341570 257006 4380636 2905370 5099232

The Wiki part of the new OEIS can be found at http://oeis.org/wiki.

Sequence A200000 was added on November 20, 2011: this is an interesting sequence concerning paths (or "meanders") through a grid.

We reached 200000 sequences at midnight on December 1, 2011, the 200000-th sequence being A201463: see the Press release.

Further details about the goals of The OEIS Foundation Inc.

The goals are repeated here, giving further details about each one.

(1) To own the intellectual property known as "The On-Line Encyclopedia of Integer Sequences" (or "OEIS").

Added October 28, 2009: NJAS has now transferred his intellectual property in the OEIS to The OEIS Foundation Inc. For details see below.

(2) To maintain the OEIS as a service that is freely accessible by the general public.

The new version of the OEIS launched on November 11, 2010 (see the announcement) can be accessed on the Internet free of charge by anyone in the world. It has the form of a "moderated wiki". Any registered user (and registration is free) can propose new sequences or modifications to existing entries. However, these proposals will not become a permanent part of the OEIS until they have been approved by a member of the Editorial Board.
People without access to the Internet can consult the OEIS via two free email services.

One of the responsibilities of The OEIS Foundation Inc. is to keep the new version of the OEIS, (or, in future years, whatever replaces it) up and running 24 hours a day, seven days a week. This will of course require maintaining all the computer programs that underlie the OEIS.

(3) To act so as to maintain its own existence indefinitely.

The trustees are to serve for a period of three years, with the option of unlimited renewals.

The trustees are to elect the officers, and new members may be added as the needs of the OEIS evolve.

The trustees are also to monitor the performance of the Editorial Board of the OEIS.

It is hoped that the OEIS will survive into the distant future, and the Trustees of The OEIS Foundation Inc. are charged with taking "the long view". This will include evolving the medium in which the OEIS is stored when that becomes necessary. Over the past 46 years the medium in which the OEIS has been stored has changed from file cards to punched cards to magnetic tape to magnetic disks, and no doubt further changes will be required in the future.

A list of members of the Board of Trustees may be found here.

(4) To collect and distribute funds in order to carry out the first three goals.

It is intended that The OEIS Foundation Inc. will be a charity and a Section 501(c)(3) tax-exempt organization. An application for tax-exempt status was filed with the Internal Revenue Service on July 2, 2009. Tax-exempt status was granted on September 10, 2009 (see the following section).

Initially the expenses will be the costs involved with setting up The OEIS Foundation Inc., filing for tax-exempt status, and in maintaining the wiki version on a web hosting site. Additional expenses will arise from publicizing the Foundation at scientific meetings.

Future expenses may include paying salaries to people to maintain the OEIS.

The OEIS Foundation Advisory Board

The OEIS Advisory Board was created on May 7, 2013, with the goal of having a group of distinguished scientists that the Board of Trustees and other members of the OEIS community can call upon for advice and guidance on matters related to the OEIS or the OEIS Foundation.

A list of the members of the Advisory Board may be found here.

The Advisors will be invited to participate in meetings of the Board of Trustees, and to vote on resolutions, although their votes will not be counted in the official tally.

To begin with, members may be added to or removed from the Advisory Board by the President after consultation with the Board of Trustees. Initially there will not be a fixed term for Advisory Board members.

At some later time, the make-up of the Advisory Board may be added to the By-Laws.

Tax-exempt status of The OEIS Foundation Inc.

We applied for tax-exempt status in the USA for The OEIS Foundation Inc. on July 2, 2009. Here is a copy of the IRS Form 1023 that we submitted, and of an attachment containing detailed responses to certain sections of that form.

On August 22, 2009, we received a letter from the IRS requesting additional information and clarification of certain points.

Neil J. A. Sloane replied on August 26, 2009, providing answers to these questions. His letter can be seen here.

On September 10, 2009, the IRS approved our request. Their letter can be seen here.

The important points are as follows:

  • The OEIS Foundation's tax identification number or EIN is 30-0562250.
  • Effective Date of Exemption: April 14, 2009. Accounting Period Ending: December 31.
  • The OEIS Foundation Inc. is exempt from Federal income tax under section 501(c)(3) of the Internal Revenue Code.
  • Contributions to the Foundation are deductible under section 170 of the Code.
  • The Foundation is also qualified to receive tax deductible bequests, devises, transfers or gifts under section 2055, 2106 or 2522 of the Code.
  • The IRS has determined that the Foundation is a public charity under section 170(b)(1)(A)(vi) of the Code.

We are very grateful to Nancy Eberhardt, Esq., Director of the New Jersey Program of the Pro Bono Partnership, for her invaluable help with all the legal matters involved in setting up and registering the OEIS Foundation.

We also thank Terry Ilardi, Esq., Copyright Counsel for the IBM Corporation (working "Pro Bono") who drafted the two license agreements that are being used with the OEIS Wiki: the OEIS Contributor's License Agreement and the OEIS End-User License. The OEIS Foundation is very grateful to him for his help.

Tax-exempt status in New Jersey

On November 3, 2009 we filed documents with various agencies of the State of New Jersey to register the OEIS Foundation Inc. as a new charity in NJ, and to apply for exemption from NJ business tax and NJ sales and use tax.
On November 12, 2009 we received a letter of exemption from NJ business tax.
On November 24, 2009 we received a letter of exemption from NJ sales and use tax.
On November 24, 2009 we also received a NJ Sales Tax Exempt Organization Certificate.
On December 2, 2009 we received a NJ New Charities Registration letter.
Copy of NJ Division of Consumer Affairs Short-Form Registration/Verification Forms CRI-200 for 2010 (filed in May 2011), 2011 (filed in July 2012), 2012 (filed in April 2013), 2013 (filed in March 2014), 2014 (filed in April 2015).

Transfer of IP in OEIS to The OEIS Foundation Inc.

The following is a slightly edited version of an announcement that NJAS made on October 27 2009 to the Trustees of The OEIS Foundation Inc.

Yesterday (Monday, October 26 2009) was a landmark day in the history of the OEIS. I transferred the intellectual property I own in the OEIS to The OEIS Foundation Inc. The letter of assignment can be seen here.

To make the transfer precise, my colleague David Applegate and I burned a DVD containing a snapshot of the whole OEIS (the sequences, of course, as well as all the associated files), which accompanies the letter of assignment as Exhibit A.

The DVD contains about 1.4GB. The main sequence file contains 164891 sequences. It is 2510785 lines long and contains 169521003 characters. There are also 10716 b-files, and the b-files and other similar files comprise 852M. Another 280M are files associated with the lookup process.

I am grateful to Terry Ilardi, Esq., of IBM Corporation (working "Pro Bono") who drafted the letter of assignment, and to David Applegate for help in creating the DVD.

Trademarking "OEIS"

On June 16, 2010, we filed applications to trademark "The On-Line Encyclopedia of Integer Sequences" and "OEIS" with the United States Patent and Trademark Office. We are very grateful to Debra A. Shelinsky Greene, Esq., Counsel, and Florence M. Niel Henits, Trademark Paralegal, both of the Trademarks and Copyrights division, Merck & Co., Inc., working "Pro Bono", who filed the applications on behalf of The OEIS Foundation.

"OEIS" was registered on February 8, 2011, as a United States Trademark (Registration Number 3,916,748). A copy of the certificate can be seen here. The Reverse side of Certificate of Registration lists requirements that we must fulfill during 2011-2021. See Annual reminders.

"THE ON-LINE ENCYCLOPEDIA OF INTEGER SEQUENCES" was registered on December 20, 2011, as a United States Trademark (Registration Number 4,072,712). A copy of the certificate can be seen here. The Reverse side of Certificate of Registration lists requirements that we must fulfill during 2011-2021. See Annual reminders.

The Fundraising Committee

At the Board of Trustees meeting on June 8, 2010, it was unanimously agreed to establish a Fundraising Committee. The goal of the committee is to raise money to support the OEIS Foundation and the On-Line Encyclopedia of Integer Sequences (the OEIS).

In particular, the goals of the Fundraising Committee are, first, to raise funds to to cover the day-to-day expenses of running the OEIS, and, second, to build up a reserve fund to ensure the long-term stability of the OEIS.

The Board of Trustees agreed to adopt the term "Advisor" to refer to people who actively participate in fundraising or make similar contributions to the operation of the OEISF, but aren't necessarily Trustees of the OEIS Foundation or Editors of the OEIS.

Committee members shall be appointed by the President of the OEIS Foundation, and members shall serve for two years, unless reappointed.

The initial committee was formed on August 29, 2010. At the present time (November 2014), the Fundraising Committee consists of David Applegate, Ronald Graham, Charles Greathouse (Chair), Ray Chandler, Neil Sloane, and Susanna Cuyler (Secretary).

To donate to The OEIS Foundation Inc.

Donations to The OEIS Foundation Inc. (tax-deductible in the USA) can be made in three ways:

  • Through PayPal, using the icon at the top right of this page.
  • Directly, with a check or money order made out to The OEIS Foundation Inc., and sent to:

    Ray Chandler,
    Treasurer, The OEIS Foundation Inc.,
    7000 Briercliff Ct.,
    Fort Worth, TX 76132, USA

  • Directly, by a wire transfer to the OEIS Foundation bank account. For information on how to do this, please contact Ray Chandler (treasurer(AT)oeisf.org) or Neil J. A. Sloane (president(AT)oeisf.org).

Keep in mind that many corporations have a fund-matching program - they will match your charitable contributions. This is an excellent way to double your donation to the OEIS Foundation!

All donations will be gratefully acknowledged on this page.

The OEIS Foundation's tax identification number or EIN is 30-0562250.

List of donors to the OEIS Foundation Inc.

AT&T has supported the OEIS almost from its beginning, by allowing Neil J. A. Sloane to maintain it from 1969 onwards and to host it on his AT&T Labs home page from 1996 through 2010; and also by allowing David Applegate to contribute his services towards maintaining the operation of the OEIS on Neil J. A. Sloane's web site at AT&T Labs and from 2010 onwards in its new home.

The OEIS Foundation Inc. is also very grateful to the following donors:

Donors in 2015

Gauss Circle Benefactors in 2015 (Gifts of $25000 and above):

Benefactors in 2015 (Gifts of $5000 and above):

   N. J. A. Sloane

Sponsors in 2015 (Gifts of $1000 and above):

   Ron Hardin

   Donald and Jill Knuth

   Zegar Family Fund

Patrons in 2015 (Gifts of $100 and above):

   Jean-François Alcover    Ray Chandler    Paul Curtz    Leo Depuydt    Eric Desbiaux    Christopher Gribble    Peter Klimek    Fred Kline    Charles F. Marion    Jerry Metzger    Jeffrey Shallit    N. J. A. Sloane (in honor of Doron Zeilberger for finding a recurrence for A253070)    Jose Tabora    Vladimir Tontchev    Doron Zeilberger (in honor of Mireille Bousquet-Mélou who came close to meeting a challenge proposed here)    Doron Zeilberger (in honor of Scott Garrabrant and Igor Pak for disproving the Noonan-Zeilberger conjecture)    Doron Zeilberger (in honor of Ferenc Balogh for completely solving a challenge raised here)    Doron Zeilberger (in honor of Paul Johnson, Marko Thiel, and Nathan Williams for meeting a challenge raised here)

Friends in 2015 (Gifts of less than $100):

   Altug Alkan    Amazon Smiles    Praveen Bhamidipati    Valerie Blair    Malachi de AElfweald    Maurizio De Leo    Pierandrea Formusa    Jeremy Gardiner    Darren Golbourn    António Gonçalves    Mats Gravnik    Merzon Grigory    Richard Grossman    Jagernot    johnathan79717@gmail.com    Daniel Krenn    Stephen N Lee    Antonio Roldan Martinez    Brett Menzies    Donald Mintz    Bas Niesink    Gerhard Riphagen    Nicholas Vasilopoulos    Yehuda Yannay    Doron Zeilberger (in honor of Ferenc Balogh for making progress on a challenge raised here)

The OEIS Foundation Inc. is also grateful to the American Mathematical Society for facilitating our access to MathSciNet in 2015.

Donors in 2014

Gauss Circle Benefactors in 2014 (Gifts of $25000 and above):

Benefactors in 2014 (Gifts of $5000 and above):

   N. J. A. Sloane

Sponsors in 2014 (Gifts of $1000 and above):

   Anonymous (2)

   Sara C. Billey

   Russ Cox

   Donald and Jill Knuth

Patrons in 2014 (Gifts of $100 and above):

   Jean-François Alcover    David Applegate    Peter Bala    Anthony Bartoletti    George Beck    JM Bergot    Ray Chandler    William Clark    Donald Craig    Gary Croft    Harvey Dale    Michael Thomas de Vlieger    Leo Depuydt    Emeric Deutsch    Robert Dickau    Karl Dilcher    Mac Fischer    Richard Forberg    Freeman-Mosher Family Fund    Xan Gregg    Christopher Gribble    Maximilian Hasler    Brian Hayes    Paul Henry    Karl Javorszky    Ed Jeffery    Clark Kimberling    Fred Kline    Stephane Legendre    Michel Marcus    Charles F. Marion    James McCarron    Jerry Metzger    John Morack    Kival Ngaokrajang    Thane Plambeck    Paula Remmel    Albert Renshaw    Jon E. Schoenfield    Richard Schroeppel    Brian N Scott    Sven Simon    Richard P. Stanley    Paul K. and Bonita K. Stockmeyer    Vinay Vaishampayan    Robert G. Wilson, v    Doron Zeilberger in honor of Lynn Chua and Krishanu Roy Sankar    Doron Zeilberger in honor of Guillaume Chapuy for proving a conjecture made by S. B. Ekhad and D. Zeilberger    Doron Zeilberger in honor of Max Ehrman (Yale University)    Doron Zeilberger in honor of Matthew Russell for his services to Experimental Mathematics    Reinhard Zumkeller

Friends in 2014 (Gifts of less than $100):

   AmazonSmile Foundation    Graham Ansell    Robin Arthan    Mohammad Azarian    Jeremy Baker    Brian Barrett    Paul Barry    Stefanus Basson    Linda Black    Murray Bremner    Pierre CAMI    Paul Cantrell    Shen Chao    Benjamin Chung    Pantelis Damianou    Charles Doncaster    David P. Durgin    Malachi de AElfweald    Lucinda Ebert    Patrick Ekman    Alejandro Erickson    Benjamin Fagin    Alexander Fainshtein    James L Farrington    Charles W P Fearnley    Yuval Filmus    Nathan Fox    Jason Fuemmeler    Eric Gottlieb    Mats Gravnik    Sandra J Green Antiques    Christopher Herzog    Ron Hubbard    Mark Hurd    Frank M Jackson    David Johnston    Leandro Junes    Karl Keller    Al Kelley    Mohammadreza Khalilighazi    Tanya Khovanova    Oleg Komarov    Leonid Kovalev    Wolfdieter Lang    William Lindgren    Peter Lindner    Robert Lyons    Richard Mabry    Robert Macartney    Antonio Roldán Martínez    Edwin McCravy    Michael Mirzayanov    Kerry Mitchell    Jacques Moussafir    Agnar Muntingh    Barbara Mutz    David Nacin    Dmitrii Pasechnik    Geof Pawlicki    Robert Raines    James Rasbold    Nicolas Rolin    Andrey Rukhin    Gunther Schrack    Richard Simmons    James Stein    Sinan Taifour    Tutoring    Roland van den Brink    Daniel Vandermast    Russell Walsmith    Jennifer Ward    Mike Weiner    Susanne Wienand    Marsha Woerner

The OEIS Foundation Inc. is also grateful to the American Mathematical Society for facilitating our access to MathSciNet in 2014.

Donors in 2013

Benefactors in 2013 (Gifts of $5000 and above):

   Anonymous

   David Scambler

   N. J. A. Sloane

Sponsors in 2013 (Gifts of $1000 and above):

   Anonymous

   Russ Cox

   Fred Kline

   Jill C Knuth

   Tony D. Noe

Patrons in 2013 (Gifts of $100 and above):

   Jean-François Alcover    David Applegate    Peter Bala    JM Bergot    Mira Bernstein    Arie Bos    Murray Bremner    Umberto Cerruti    Benjamin Chaffin    Ray Chandler    Charles K. Cook    Donald Craig    Gary Croft    David Crookes    Paul Curtz    Harvey Dale    Leo Depuydt    Emeric Deutsch    Robert Dickau    Federico Echenique (in honor of Doron Zeilberger)    Rémi Eismann    Xan Gregg    Christopher Gribble    Paul Hanna    Brian Hayes    Alois Heinz    Sean Irvine    William Keith    Clark Kimberling    Ron Knott    Marc LeBrun    Stéphane Legendre    Francis Maleval    Michel Marcus    Charles F. Marion    Johannes Meijer    Kival Ngaokrajang    Omar Evaristo Pol    Jeffrey Remmel    Steve Roberts    Brian N Scott    Sven Simon    Aksel Soee    Ralf Stephan    Paul K. and Bonita K. Stockmeyer    Timothy Vaughan    David Wilson    Eric Wolman    Doron Zeilberger (on behalf of the many corrections and solutions of challenging problems by students in his class)    Doron Zeilberger (in honor of Josh Smith, Rutgers University Math Dept's dedicated computer guru)    Reinhard Zumkeller

Friends in 2013 (Gifts of less than $100):

   Mohammad Azarian    Michael Behrend    Philipp Blume    Jonathan Bright    Stefano Capparelli    Don Cohen    Zoa Conner    Bruce Dearden    Eric Desbiaux    Aditya Dhakal    David Durgin    David Edwards    Louis Emery    James L Farrington    Tim Fulford    Jeremy Gardiner    Silvio Gnepf    Merzon Grigory    Rick Gutleber    Maryann Haskell    Enrique Pérez Herrero    Stewart Herring    Robert Inventor    Frank M Jackson    Mamuka Jibladze    David Johnston    Lucy Ann Jones    Michael Kaarhus    Alvin Khaled    Antti Karttunen    Tanya Khovanova    Anthony Labarre    Wolfdieter Lang    Silvio Levy    Brian Lewis    Makefoil Ebooks    Peter Mao    Joseph Marasco    Jessica Mckellar    John Miller    Kerry Mitchell    David Moews    David Nacin    Mircea-Cristian Nuca    Christian Perfect    Boris Putievskiy    James Rasbold    Rainer Rosenthal    Richard Schroeppel    David Spies    James Stein    Robert Tanniru    Lenny Tevlin    Seth Troisi    Mark Underwood    Willy Van den Driessche    Jeroen van der Burg    Russell Walsmith    Mike Weiner    Thomas Wieder    Shi Yong

The OEIS Foundation Inc. is also grateful to the American Mathematical Society for facilitating our access to MathSciNet in 2013.

Donors in 2012

Benefactors in 2012 (Gifts of $5000 and above):

   Joerg Arndt

   Neil J. A. Sloane

Sponsors in 2012 (Gifts of $1000 and above):

   The American Mathematical Society

   Anonymous

   Russ Cox

   Paul Curtz

   Charles R Greathouse IV

   Jill Knuth

   Tony D. Noe

Patrons in 2012 (Gifts of $100 and above):

   David Applegate    Peter Bala    Manuel Blum    Benjamin Chaffin    Ray Chandler/Dell Giving    Benoit Cloitre    Donald Craig    David Crookes    Emeric Deutsch    Tom Duff    Robert Dickau    Rémi Eismann    Gardenia Giacoman    Google Matching Gifts Program    Xan Gregg    Claus Johansen    Clark Kimberling    Michael Kleber    Peter Klimek    Fred Kline    Kenneth Knowlton    Jaume Oliver Lafont    Charles F. Marion    James McCarron    John F. Morack    Omar Evaristo Pol    George Purdy    Albert Renshaw    Brian M. Scott    Richard P. Stanley    Vinay Vaishampayan    Matthew Vandermast    Robert G. Wilson, v    Doron Zeilberger    Reinhard Zumkeller

Friends in 2012 (Gifts of less than $100):

   Jean-François Alcover    Stuart Anderson    Mohammad Azarian    Ralph Baggett    Michael Behrend    Lawrence Biroff    Matthew Brin    Michael Cavers    Tyler Curtain    Eames Demetrios    Dave Durgin    Patrick Ekman    Yuval Filmus    Anant Godbole    Enrique Pérez Herrero    Frank M. Jackson    Loic Jegouzo    Vaclav Kotesovec    Leonid Kovalev    Wolfdieter Lang    Robert Lyons    Matevz Markovic    Antonio Roldán Martínez    Lance Menthe    John W. Morse    Eric Moyer    Joan New    Kival Ngaokrajang    Emily Norton    David Penman    Tibor Djurica Potpara    Robert Price    Manda Riehl    Rainer Rosenthal    Marc Rosner    Albert Rossinski    Roland Schröder    Richard Schroeppel    Keith Smith    Anatol Tirkel    Tan You Tong    Patrick Warren    Thomas Wieder    Wilhelm Wijkander    Joshua Zucker

The OEIS Foundation Inc. is also grateful to the American Mathematical Society for facilitating our access to MathSciNet in 2012.

Donors in 2011

Benefactors in 2011 (Gifts of $5000 and above):

Sponsors in 2011 (Gifts of $1000 and above):

   Bruno Berselli

   Donald and Jill Knuth

   Tony D. Noe

   Neil J. A. Sloane

Patrons in 2011 (Gifts of $100 and above):

   Matt C. Anderson    Anonymous    Martin Betz    Pierre CAMI    Ray Chandler    Benoit Cloitre    Russ Cox    David Crookes    Paul Curtz    Harvey P. Dale    Carl de Marcken    Dell Giving (Matching Fund)    Emeric Deutsch    Dan Drake    Jeremy Gardiner    Olivier GERARD    Google Matching Gifts Program    Toby Gottfried    Xan Gregg    Christopher Gribble    Alois Heinz    Wolfgang Hintze    Donovan Johnson    Antti Karttunen    Clark Kimberling    Fred Kline    Leonid Kovalev    Marc LeBrun    Shawn Ligocki    Stephen Marak    Charles F. Marion    Johannes Meijer    Will Nicholes    Paul Nick    Ed Pegg, Jr.    Enrique Pérez Herrero    Thane Plambeck    Omar Pol    Bradley Robinson    Phil Rutschman    Bill Sanford    David Scambler    Bent Schmidt-Nielsen    Brian M. Scott    Allen Stenger    William D. Tisdale    Vinay Vaishampayan    David W. Wilson    Robert G. Wilson, v    Reinhard Zumkeller

Friends in 2011 (Gifts of less than $100):

   Jeremy Albright    Jean-François Alcover    Gadi Aleksandrowicz    Anonymous    David L. Applegate    Mohammad K. Azarian    Gary Baydo    Gerard Blais    David Brown    Marvin Ray Burns    Alessandro De Luca    Joel Dubiner    Theresia Eisenkoelbl    Patrick C. Ekman    Ruy Fabila    Wei Fang    Richard Grafen    Mats Granvik    JoAnne Growney    Paul Hanna    Stewart Herring    Meyer Jacobs    Ed Jeffery    Sudhir Jha    David Russell Johnston    Carel Jonkhout    Ilmari Karonen    William Keith    Fred Kline    Przemyslaw Kobylanski    Mikko Korhonen    Vaclav Kotesovec    Peter Kosinar    Denis Krotov    Wolfdieter Lang    John W. Layman    David Madore    Peter Mao    William McEachen    Lorenz Milla    Kerry Mitchell    Alejandro Henry Morales    Susan Murray    David Nacin    Philip Newton    Tibor Djurica Potpara    Andrew Poynter    James Raymond    Gerhard Riphagen    Andrew Rodland    Rainer Rosenthal    Matthew Samuel    Richard Schroeppel    Zechao Shang    Louis Shapiro    Bob Smith    Pieter Stadhouders    Einar Steingrimsson    William Summer    Lenny Tevlin    Willy Van den Driessche    Sjoerd Visscher    Al Vilcius    Christof Weber    Dennis P. Walsh    Susanne Wienand    Mike Weiner    Robin Whitty

Donors in 2010

The OEIS Foundation Inc. thanks the Elwyn and Jennifer Berlekamp Fund at the East Bay Community Foundation for a very generous grant for General Support, on June 23 2010.

The OEIS Foundation Inc. is grateful to Marc LeBrun for two very generous donations on Nov. 23 2009 and April 7 2010, and to Adobe Systems Inc. for matching his donations.

   Anonymous (2)    Gary W. Adamson    David L. Applegate    Mohammad K. Azarian    The Elwyn and Jennifer Berlekamp Fund at the East Bay Community Foundation    Benoit Cloitre    David Crookes    Eric Desbiaux    Emeric Deutsch    Robert Dickau    Rémi Eismann    Jeremy Gardiner    Christopher Gribble    Paul Hanna    George Hart    Dan Kalman    Antti Karttunen    Reed Kelly    Clark Kimberling    John Layman    Marc LeBrun    Kevin McCoy    Kerry Mitchell    Tony D. Noe    Thane Plambeck    Christopher Rebert    Rich Schroeppel    Sven Simon    Neil J. A. Sloane    Paul K. and Bonita K. Stockmeyer    Kent Vander Velden    Thomas Wieder

Donors in 2009

   Ray Chandler    Jeremy Gardiner    Ronald and Fan Graham    Christopher Gribble    Brian Hayes    Marc LeBrun    Charles F. Marion    Pacha Nambi    Tony D. Noe    Warut Roonguthai    Rainer Rosenthal    Neil J. A. Sloane    Andrew Weimholt    Thomas Wieder    Reinhard Zumkeller

Annual reminders

  • The Board of Trustees of the OEIS Foundation Inc. must hold a board meeting at least once each year.
    The meeting may be electronic as long as all trustees participate.
    Board meetings were held on June 29, 2009; July 6, 2009; December 22, 2009; June 8 2010, November 29, 2011; February 16, 2012; February 19, 2013; June 28, 2013; February 18, 2014.
  • The OEIS Foundation Inc. must file an income tax statement with the Internal Revenue Service of the USA once a year. Provided the gross receipts are $50,000 or less, the Foundation can use the e-Postcard Form 990-N. The fiscal year for the OEIS Foundation Inc. runs from January 1 to December 31. The tax statement must be filed by April 30 of the following year. The Foundation's Employee Identification Number (EIN) is 30-0562250. See the Foundation's IRS Form 990-N for 2009, IRS Form 990-N for 2010, IRS Form 990-N for 2011, IRS Form 990-N for 2012, IRS Form 990-N for 2013. IRS Form 990-N for 2014.
  • The OEIS Foundation Inc. must renew its registration as a New Jersey charity each year. Provided the gross receipts are $25,000 or less, the Foundation can use the Short-Form Registration/Verification Statement Form CRI-200. See links to copies of our NJ Division of Consumer Affairs Forms CRI-200 for earlier years at the top of this web page. If the gross receipts are more than $25,000, the Foundation must use the CRI-300R Long Form Renewal Registration. To download the blank form, go to http://www.njconsumeraffairs.gov/ocp/charities.htm, then Registration Forms and Instructions, then scroll down to either the CRI-200 or CRI-300R Form. The Foundation's N.J. Charities Registration Number is CH-3228900.
  • The OEIS Foundation Inc. must file an annual report with the State of NJ, Dept. of the Treasury, Division of Revenue, each year.
    To do this, go to www.nj.gov/treasury/revenue/, click on "I want to", and go to "File Annual Reports", then "Continue"
    Three things must be filled in on the first page:
    NJ 10-digit ID: 0101000611
    Type of Entity: New Jersey Non Profit, NP
    Formation Date: 04/2009
    On July 19 2011, Neil J. A. Sloane did this and paid 2 X $25 = $50 for 2010 and 2011. On July 3 2012, Neil J. A. Sloane did this and paid $25 for 2012 (see Receipt). On Feb. 6 2013, Neil J. A. Sloane did this and paid $25 for 2013. On Feb. 15 2014, Neil J. A. Sloane did this and paid $25 for 2014 (see Receipt). On Mar. 27 2015, Neil J. A. Sloane did this and paid $25 for 2015 (see Receipt).
  • The Reverse side of Certificate of Registration of the trademark "OEIS" lists requirements that the Foundation must fulfill during 2011-2021. (1) The Foundation must file a Declaration of Use between February 8, 2016 and February 8, 2017. (2) The Foundation must file a Declaration of Use and an Application for Renewal between February 8, 2020 and February 8, 2021.
  • The Reverse side of Certificate of Registration of the trademark "THE ON-LINE ENCYCLOPEDIA OF INTEGER SEQUENCES" lists requirements that the Foundation must fulfill during 2011-2021. (1) The Foundation must file a Declaration of Use between December 20, 2016 and December 20, 2017. (2) The Foundation must file a Declaration of Use and an Application for Renewal between December 20, 2020 and December 20, 2021.

The OEIS posters

There are now three posters. They may be downloaded without charge, and make excellent wall decorations.

  • OEIS.org 2014 (11" x 17"). A new poster, illustrating nine recent sequences (out of a quarter of a million); created by Neil J. A. Sloane in December 2014.
  • Key to OEIS.org 2014 poster (8.5" x 11")
  • Blue poster for The OEIS Foundation Inc. (11" x 17"). This is the second version, created by Lucas Garron (then at Stanford University) in May 2010.
  • The original Poster for The OEIS Foundation Inc. (11" x 17"). This is the first version, created by David Applegate and Neil J. A. Sloane in September 2009. It is still our favorite.
  • Small version of the original poster. (8.5" x 11")
  • Key to the original poster (8.5" x 11")

    • OEIS: The Movie

    To celebrate the launching of the OEIS Foundation, Tony Noe made an 8.5-minute movie showing the first 1000 terms of 1000 sequences, with soundtrack from Recaman's sequence A5132. There are four ways to view the movie:

    1. On YouTube (you can always find it by searching for "OEIS Movie").
    2. By downloading a 5 MB QuickTime movie that is viewable with QuickTime Player 7 and some browsers.
    3. By downloading a 27 MB movie that uses the H264 codec and AAC sound. This movie is viewable on recent versions of Windows Media Player and most up-to-date browsers.
    4. By going to Tony Noe's website for a frame-by-frame display, with links to the OEIS definition of each sequence.

    (Incidentally, you can convert the movie to just about any other format at http://www.media-convert.com, without downloading any software).

    To contact the OEIS Foundation.

    For financial matters, direct contributions, donations, please contact:

    Ray Chandler,
    Treasurer, The OEIS Foundation Inc.,
    7000 Briercliff Ct.,
    Fort Worth, TX 76132, USA
    Email address: treasurer(AT)oeisf.org or rayjchandler(AT)sbcglobal.net

    For anything else, please contact:

    Neil J. A. Sloane,
    President,
    The OEIS Foundation Inc.,
    11 South Adelaide Avenue,
    Highland Park, NJ 08904, USA
    Email: president(AT)oeisf.org or njasloane(AT)gmail.com. Phone: (732) 828 6098.

    About this page.

    This page is maintained by Neil J. A. Sloane, President, The OEIS Foundation Inc.

    2009: Created on Aug 25, 2009. Update about IRS tax-free status added Sep 17, 2009. Links to poster and key to poster added Oct 1, 2009. Updates about the transfer of IP in OEIS to The OEIS Foundation Inc. added Oct 28, 2009. Press release added Nov 14, 2009. Letter confirming NJ tax-exempt status added Nov 17, 2009. List of donors was begun on Dec 2, 2009. Information about registering as a NJ charity added Dec 8, 2009. Budget for 2009-2010 revised Dec 20, 2009. The bylaws were amended and five governance policies were adopted at the Board of Trustees meeting on Dec 22, 2009.

    2010: Information about the license agreements for users of the OEIS Wiki was added Feb 13, 2010. Information about the OEIS movie updated Mar 12 2010. Information about the OEIS Wiki updated Jun 8, 2010. Information about the June 8, 2010 Board of Trustees meeting added Jun 10, 2010 Information about applying for trademarks added Jun 18, 2010. Information about posters revised Jun 26, 2010. Information about Fundraising Committee revised, Aug 29, 2010. Information about the new OEIS added Nov 22, 2010.

    2011: Status report on new OEIS added Jan 12 2011 and updated Jan 18 2011. Apr 23, 2011: Added copies of income tax returns (Form 990-N) for 2009 and 2010. Added section about annual reminders. Updated information about trademarks. May 8, 2011: Divided list of donors (for 2011 onwards) into four categories. Added copy of NJ Form CRI-200 for 2010. Dec 3, 2011: Added Press release about reaching 200,000 sequences. Dec 5, 2011: Added dates on which meetings of the Board of Trustees have been held.

    2012: Jan 11, 2012: Added information about the approval of the second trademark application. Jan 24, 2012: Minor editorial and formatting changes. Feb 2, 2012: Following a suggestion from Günther Leenaert, reformatted page in css style with assistance from AT&T colleague Farheen Masood. Feb 16, 2012: Financial report for 2011, budget for 2012, new trustees (Greathouse and Munafo). Mar 26, 2012: Added information about 2011 income tax return (Form 990-N). Jul 21, 2012: Added copy of NJ Form CRI-200 for 2011.

    2013: Feb 19, 2013: Added financial report for 2012. Feb 25, 2013: Added information about board meeting held Feb 19 2013. Apr 1, 2013: Added information about 2012 income tax return (Form 990-N). Apr 14, 2013: Added copy of NJ Form CRI-200 for 2012. May 7, 2013: Added information about Advisory Board.

    2014: Feb 8, 2014: Added financial report for 2013. Feb 15, 2014: Added information about filing Annual Report for 2014 to NJ Division of Revenue. Feb 18, 2014: Added information about board meeting held Feb 18 2014; updated name and address of Treasurer. Mar 16-21, 2014: Added copy of NJ Form CRI-300R and IRS Form 990-N for 2013.

    2015: Feb 26, 2015: Added information about Riordan Prize. Mar 28, 2015: Added information about 2014 income tax return (Form 990-N). Apr 14, 2015: Added copy of 2014 NJ Form CRI-200 and Treasurer's Report for 2014.