A022620 - OEIS

A022620

Expansion of Product_{m>=1} (1+q^m)^(-25).

1, -25, 300, -2325, 13275, -60655, 235525, -811975, 2558575, -7502175, 20713560, -54345175, 136483700, -329961200, 771284950, -1749490965, 3862641850, -8322360350, 17536187475, -36204137625, 73353404555, -146061623800, 286183499350, -552361219950, 1051231017350

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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(5) * exp(5*Pi*sqrt(n/6)) / (2^(7/4) * 3^(1/4) * n^(3/4)). - Vaclav Kotesovec, Aug 27 2015

MATHEMATICA

nmax = 50; CoefficientList[Series[Product[1/(1 + x^k)^25, {k, 1, nmax}], {x, 0, nmax}], x] (* Vaclav Kotesovec, Aug 27 2015 *)

CROSSREFS

Sequence in context: A079873 A078488 A010941 * A367457 A042206 A269448

Adjacent sequences: A022617 A022618 A022619 * A022621 A022622 A022623

KEYWORD

sign

AUTHOR

N. J. A. Sloane

STATUS

approved