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Expansion of Product_{m>=1} (1+q^m)^(-31).
2

%I #14 Feb 15 2018 08:12:51

%S 1,-31,465,-4526,32426,-184357,877052,-3633851,13513458,-46099108,

%T 146495398,-438514468,1246964119,-3391183930,8867709030,-22393552057,

%U 54808232438,-130404256148,302394884204,-684929956630,1518203338688

%N Expansion of Product_{m>=1} (1+q^m)^(-31).

%H G. C. Greubel, <a href="/A022626/b022626.txt">Table of n, a(n) for n = 0..1000</a>

%F a(n) ~ (-1)^n * 31^(1/4) * exp(Pi*sqrt(31*n/6)) / (2^(7/4) * 3^(1/4) * n^(3/4)). - _Vaclav Kotesovec_, Aug 27 2015

%t nmax = 50; CoefficientList[Series[Product[1/(1 + x^k)^31, {k, 1, nmax}], {x, 0, nmax}], x] (* _Vaclav Kotesovec_, Aug 27 2015 *)

%K sign

%O 0,2

%A _N. J. A. Sloane_