%I #7 Nov 29 2017 03:41:19
%S 1,1,1,3,5,8,12,20,33,50,74,114,175,257,375,555,814,1171,1677,2406,
%T 3435,4855,6825,9591,13428,18667,25851,35745,49250,67544,92340,125966,
%U 171345,232257,313945,423470,569778,764465,1023231,1366827,1821756,2422394,3214318,4257088,5627086,7422941
%N Expansion of Product_{k>=1} ((1 + x^(2*k-1))/(1 - x^(2*k)))^k.
%F G.f.: Product_{k>=1} ((1 + x^(2*k-1))/(1 - x^(2*k)))^k.
%F G.f.: exp(Sum_{k>=1} x^k*((-1)^(k+1) + x^k)/(k*(1 - x^(2*k))^2)).
%F a(n) ~ exp(3 * (7*Zeta(3))^(1/3) * n^(2/3) / 4 + Pi^2 * n^(1/3) / (24 * (7*Zeta(3))^(1/3)) - Pi^4 / (12096 * Zeta(3)) + 1/12) * (7*Zeta(3))^(7/36) / (A * 2^(23/24) * sqrt(3*Pi) * n^(25/36)), where A is the Glaisher-Kinkelin constant A074962. - _Vaclav Kotesovec_, Nov 28 2017
%t nmax = 45; CoefficientList[Series[Product[((1 + x^(2 k - 1))/(1 - x^(2 k)))^k, {k, 1, nmax}], {x, 0, nmax}], x]
%t nmax = 45; CoefficientList[Series[Exp[Sum[x^k ((-1)^(k + 1) + x^k)/(k (1 - x^(2 k))^2), {k, 1, nmax}]], {x, 0, nmax}], x]
%Y Cf. A000219, A006950, A113415, A156616, A224364, A263140, A273225, A273226, A274621, A295831.
%K nonn
%O 0,4
%A _Ilya Gutkovskiy_, Nov 28 2017