|
|
2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
0,1
|
|
|
COMMENTS
|
Multiplicative with a(p^e) = 0. - Mitch Harris, Jun 09 2005
Also decimal expansion of 1/5, with keyword cons. - Wolfdieter Lang, Jan 19 2023
|
|
|
REFERENCES
|
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
|
|
|
LINKS
|
James Spahlinger, Table of n, a(n) for n = 0..10000
Norman L. de Forest, The Square Root of 4 to a Million Places, Project Gutenberg EBook 3651, 2003.
Daniele A. Gewurz and Francesca Merola, Sequences realized as Parker vectors of oligomorphic permutation groups, J. Integer Seqs., Vol. 6, 2003.
Chai Wah Wu, Can machine learning identify interesting mathematics? An exploration using empirically observed laws, arXiv:1805.07431 [cs.LG], 2018.
|
|
|
FORMULA
|
a(n) = 2*A000007(n) = (-1)^A000040(n) + 1. - Juri-Stepan Gerasimov, Oct 29 2009
|
|
|
MATHEMATICA
|
PadRight[{2}, 104] (* or *)
Array[(-1)^Prime@ # + 1 &, 105] (* Michael De Vlieger, Aug 15 2018 *)
|
|
|
PROG
|
(Haskell)
a000038 n = 2 * a000007 n -- James Spahlinger, Oct 08 2012
(PARI) a(n)=if(n, 0, 2) \\ Charles R Greathouse IV, Oct 09 2012
|
|
|
CROSSREFS
|
Cf. A007395, A000007.
Sequence in context: A340851 A130779 A130706 * A335462 A353349 A349399
Adjacent sequences: A000035 A000036 A000037 * A000039 A000040 A000041
|
|
|
KEYWORD
|
easy,nonn,mult
|
|
|
AUTHOR
|
N. J. A. Sloane
|
|
|
STATUS
|
approved
|
|
