OFFSET
0,2
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..424
FORMULA
G.f.: Product_{n>=1} (1-q^n)^(3*A110163(n)/8).
a(n) ~ (-1)^(n+1) * c * exp(Pi*sqrt(3)*n) / n^(11/8), where c = 3^(7/4) * Gamma(1/3)^(27/4) / (64 * 2^(3/8) * Pi^(9/2) * Gamma(5/8)) = 0.2574920621515873836544977885672468081360882154861344422709504189964... - Vaclav Kotesovec, Jul 09 2017, updated Mar 05 2018
MATHEMATICA
nmax = 20; CoefficientList[Series[(1 + 240*Sum[DivisorSigma[3, k]*x^k, {k, 1, nmax}])^(3/8), {x, 0, nmax}], x] (* Vaclav Kotesovec, Jul 09 2017 *)
CROSSREFS
KEYWORD
sign
AUTHOR
Seiichi Manyama, Jul 02 2017
STATUS
approved