This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A261451 #7 Aug 23 2015 11:33:23
%S A261451 1,4,14,44,124,328,824,1980,4590,10320,22584,48268,101016,207432,
%T A261451 418704,832032,1629764,3150280,6014998,11354084,21204488,39206168,
%U A261451 71811256,130369900,234704360,419195412,743085912,1307823672,2286094704,3970174648,6852048368
%N A261451 Expansion of Product_{k>=1} ((1+x^k)/(1-x^k))^(k+1).
%C A261451 Convolution of A005380 and A219555.
%H A261451 Vaclav Kotesovec, <a href="/A261451/b261451.txt">Table of n, a(n) for n = 0..1000</a>
%F A261451 a(n) ~ (7*Zeta(3))^(13/36) * exp(1/12 - Pi^4/(336*Zeta(3)) + Pi^2 * n^(1/3) / (2^(5/3) * (7*Zeta(3))^(1/3)) + 3/2 * ((7*Zeta(3))/2)^(1/3) * n^(2/3)) / (A * 2^(35/18) * 3^(1/2) * Pi * n^(31/36)), where Zeta(3) = A002117 and A = A074962 is the Glaisher-Kinkelin constant.
%t A261451 nmax = 40; CoefficientList[Series[Product[((1+x^k)/(1-x^k))^(k+1), {k, 1, nmax}], {x, 0, nmax}], x]
%Y A261451 Cf. A156616, A005309, A261386, A261452, A261389.
%K A261451 nonn
%O A261451 0,2
%A A261451 _Vaclav Kotesovec_, Aug 19 2015