A286813 - OEIS

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A286813

Number of positive odd solutions to equation x^2 + 8*y^2 = 8*n + 9.

1, 1, 0, 1, 0, 0, 1, 0, 1, 1, 1, 1, 0, 0, 1, 1, 0, 0, 1, 0, 0, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1, 0, 0, 0, 1, 0, 2, 0, 0, 1, 0, 0, 0, 0, 1, 2, 0, 0, 1, 1, 0, 1, 1, 1, 1, 1, 0, 0, 1, 0, 1, 0, 0, 2, 0, 0, 1, 0, 0, 2, 0, 0, 0, 0, 1, 0, 1, 0, 1, 1, 1, 1, 0, 1, 1, 0, 2, 0

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OFFSET

0,37

LINKS

Seiichi Manyama, Table of n, a(n) for n = 0..10000

Simon Plouffe, Conjectures of the OEIS, as of June 20, 2018.

FORMULA

Expansion of q^(-9/8) * (eta(q^2) * eta(q^16))^2 / (eta(q) * eta(q^8)) in powers of q.

Euler Transform of -(-2*x^8-x^7-1)/(x^9+x^8+x+1) (o.g.f.). - Simon Plouffe, Jun 23 2018

CROSSREFS

Related to the number of positive odd solutions to equation x^2 + k*y^2 = 8*n + k + 1: A008441 (k=1), A033761 (k=2), A033762 (k=3), A053692 (k=4), A033764 (k=5), A259896 (k=6), A035162 (k=7), this sequence (k=8).

Sequence in context: A363711 A216279 A025441 * A176891 A219486 A284574

Adjacent sequences: A286810 A286811 A286812 * A286814 A286815 A286816

KEYWORD

nonn

AUTHOR

Seiichi Manyama, May 28 2017

STATUS

approved