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 A301556 #11 Oct 25 2018 11:08:32
%S A301556 1,2,12,42,154,498,1640,4990,15092,43840,125220,348478,954294,2561714,
%T A301556 6776404,17644494,45338734,114971434,288148860,713968998,1750662814,
%U A301556 4249685398,10219662844,24356466418,57558783492,134922807056,313842321696,724651728916
%N A301556 Expansion of Product_{k>=1} ((1 + x^k)/(1 - x^k))^(sigma_2(k)).
%C A301556 Convolution of A275585 and A288414.
%H A301556 Seiichi Manyama, <a href="/A301556/b301556.txt">Table of n, a(n) for n = 0..5000</a>
%F A301556 a(n) ~ exp(2^(5/4) * Pi * Zeta(3)^(1/4) * n^(3/4)/3 - Pi*n^(1/4) / (3 * 2^(13/4) * Zeta(3)^(1/4)) + Zeta(3)/(8*Pi^2)) * Zeta(3)^(1/8) / (2^(15/8) * n^(5/8)).
%t A301556 nmax = 40; CoefficientList[Series[Product[((1+x^k)/(1-x^k))^DivisorSigma[2, k], {k, 1, nmax}], {x, 0, nmax}], x]
%Y A301556 Cf. A001157, A275585, A288414.
%K A301556 nonn
%O A301556 0,2
%A A301556 _Vaclav Kotesovec_, Mar 23 2018