%I #11 Oct 10 2024 05:36:08
%S 1,2,2,4,4,4,12,8,8,16,24,24,24,32,32,64,64,64,80,80,112,160,160,160,
%T 224,224,256,320,416,416,480,576,576,704,768,896,1152,1216,1280,1536,
%U 1600,1856,2112,2304,2560,3200,3456,3584,4224,4480,5120,5760,6144,6656,7808,9088
%N G.f.: Sum_{k>=0} 2^k * x^(k*(k+1)/2) * Product_{j=1..k} (1 + x^j).
%H Vaclav Kotesovec, <a href="/A376944/b376944.txt">Table of n, a(n) for n = 0..10000</a>
%F a(n) ~ sqrt(1 + sqrt(3)) * exp(sqrt((2*log(2)^2 + 2*log(1 - sqrt(3)/2) * log(sqrt(3) - 1) + 4*polylog(2, sqrt(3) - 1) - Pi^2/3)*n)) / (4*3^(1/4)*sqrt(n)).
%t nmax = 60; CoefficientList[Series[Sum[2^k * x^(k*(k+1)/2) * Product[1+x^j, {j, 1, k}], {k, 0, Sqrt[2*nmax]}], {x, 0, nmax}], x]
%t nmax = 60; p = 1; s = 1; Do[p = Normal[Series[2*p*(1 + x^k) * x^k, {x, 0, nmax}]]; s += p; , {k, 1, Sqrt[2*nmax]}]; Take[CoefficientList[s, x], nmax + 1]
%Y Cf. A032302, A053261, A376943, A376945.
%K nonn
%O 0,2
%A _Vaclav Kotesovec_, Oct 10 2024