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 A320972 #18 Oct 27 2018 01:08:31
%S A320972 1,-2,-8,-2,30,110,92,-182,-976,-2064,-1488,3714,17618,35814,37680,
%T A320972 -25278,-216910,-541538,-819268,-480334,1441634,5924858,12518720,
%U A320972 16883366,7972200,-32275008,-120780700,-250726492,-349220282,-229745138,424373412,1958370998,4418456156
%N A320972 Expansion of Product_{k>=1} ((1 - x^k)/(1 + x^k))^(sigma_2(k)).
%H A320972 Seiichi Manyama, <a href="/A320972/b320972.txt">Table of n, a(n) for n = 0..10000</a>
%o A320972 (PARI) N=99; x='x+O('x^N); Vec(prod(k=1, N, ((1-x^k)/(1+x^k))^sigma(k, 2)))
%Y A320972 Convolution inverse of A301556.
%Y A320972 Product_{k>=1} ((1 - x^k)/(1 + x^k))^(sigma_b(k)): A320908 (b=0), A320971 (b=1), this sequence (b=2).
%Y A320972 Cf. A001157, A288389, A288422.
%K A320972 sign
%O A320972 0,2
%A A320972 _Seiichi Manyama_, Oct 25 2018