A022622 - OEIS

A022622

Expansion of Product_{m>=1} (1+q^m)^(-27).

1, -27, 351, -2952, 18279, -90234, 376065, -1380861, 4603419, -14211732, 41168493, -112989411, 296067411, -745157691, 1809973404, -4259279106, 9741879531, -21715736634, 47285714262, -100777640049, 210581729640, -432065248731, 871606288422, -1730764207107, 3386501241606

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OFFSET

0,2

LINKS

G. C. Greubel, Table of n, a(n) for n = 0..1000

FORMULA

a(n) ~ (-1)^n * sqrt(3) * exp(3*Pi*sqrt(n/2)) / (2^(7/4) * n^(3/4)). - Vaclav Kotesovec, Aug 27 2015

MATHEMATICA

nmax = 50; CoefficientList[Series[Product[1/(1 + x^k)^27, {k, 1, nmax}], {x, 0, nmax}], x] (* Vaclav Kotesovec, Aug 27 2015 *)

CROSSREFS

Sequence in context: A339250 A202289 A010943 * A030648 A223278 A278091

Adjacent sequences: A022619 A022620 A022621 * A022623 A022624 A022625

KEYWORD

sign

AUTHOR

N. J. A. Sloane

STATUS

approved