A004420 Expansion of (Sum_{n=-inf..inf} x^(n^2))^(-19).

1, -38, 760, -10640, 117002, -1075248, 8582224, -61061440, 394559320, -2348001494, 13008061200, -67666510320, 332809029680, -1556541579760, 6955832361824, -29820933412800, 123079426294922, -490508040685920

Offset

0,2

Links

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

Formula

a(n) ~ (-1)^n * exp(Pi*sqrt(m*n)) * m^((m+1)/4) / (2^(3*(m+1)/2) * n^((m+3)/4)), set m = 19 for this sequence. - Vaclav Kotesovec, Aug 18 2015

Mathematica

nmax = 30; CoefficientList[Series[Product[((1 + (-x)^k)/(1 - (-x)^k))^19, {k, 1, nmax}], {x, 0, nmax}], x] (* Vaclav Kotesovec, Aug 18 2015 *)

Crossrefs

Sequence in context: A162166 A162392 A010990 * A020930 A104761 A270500

Adjacent sequences: A004417 A004418 A004419 * A004421 A004422 A004423

Keyword

sign

Author

N. J. A. Sloane

Status

approved