|
| |
|
|
A005145
|
|
n copies of n-th prime.
|
|
7
|
|
|
|
2, 3, 3, 5, 5, 5, 7, 7, 7, 7, 11, 11, 11, 11, 11, 13, 13, 13, 13, 13, 13, 17, 17, 17, 17, 17, 17, 17, 19, 19, 19, 19, 19, 19, 19, 19, 23, 23, 23, 23, 23, 23, 23, 23, 23, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31
(list;
table;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
1,1
|
|
|
COMMENTS
|
a = A000040(A002024) - Joseph Biberstine (jrbibers(AT)indiana.edu), Aug 14 2006
Seen as a triangle read by rows: T(n,k) = A000040(n), 1<=k<=n; row sums = A033286; central terms = A031368. [From Reinhard Zumkeller, Aug 05 2009]
|
|
|
REFERENCES
|
Douglas Hofstadter, "Fluid Concepts and Creative Analogies: Computer Models of the Fundamental Mechanisms of Thought".
|
|
|
LINKS
|
Reinhard Zumkeller, Rows n = 1..125 of triangle, flattened
|
|
|
FORMULA
|
a(n) = Prime[Floor[1/2 + Sqrt[2*n]]] (* Joseph Biberstine (jrbibers(AT)indiana.edu), Aug 14 2006 *)
Flatten[Table[Table[Prime[n], {n}], {n, 12}]] (* Alonso del Arte, Jan 18 2012 *)
|
|
|
MATHEMATICA
|
Table[Prime[Floor[1/2 + Sqrt[2*n]]], {n, 1, 80}] - Joseph Biberstine (jrbibers(AT)indiana.edu), Aug 14 2006
Flatten[Table[Table[Prime[n], {n}], {n, 20}]] (* Harvey P. Dale, Dec 29 2012 *)
|
|
|
PROG
|
(Haskell)
a005145 n k = a005145_tabl !! (n-1) !! (k-1)
a005145_row n = a005145_tabl !! (n-1)
a005145_tabl = zipWith ($) (map replicate [1..]) a000040_list
a005145_list = concat a005145_tabl
-- Reinhard Zumkeller, Jul 12 2014, Mar 18 2011, Oct 17 2010
|
|
|
CROSSREFS
|
Cf. A002024.
Cf. A175944.
Sequence in context: A053046 A261179 A066658 * A156350 A076367 A098567
Adjacent sequences: A005142 A005143 A005144 * A005146 A005147 A005148
|
|
|
KEYWORD
|
nonn,nice,tabl
|
|
|
AUTHOR
|
Russ Cox
|
|
|
STATUS
|
approved
|
| |
|
|
