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A000038 Twice A000007.
(Formerly M0004)
26
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
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.
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
Sequence in context: A340851 A130779 A130706 * A335462 A353349 A349399
KEYWORD
easy,nonn,mult
AUTHOR
STATUS
approved

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Last modified March 28 11:59 EDT 2024. Contains 371254 sequences. (Running on oeis4.)