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 A288422 #22 Sep 08 2022 08:46:19
%S A288422 1,-1,-4,-6,0,24,51,89,47,-152,-578,-1149,-1482,-738,2384,8901,18476,
%T A288422 26774,24151,-7143,-86804,-226605,-406442,-539872,-441822,181268,
%U A288422 1671148,4240334,7618777,10551340,10218856,1973258,-20190349,-61492391,-121880826
%N A288422 Expansion of Product_{k>=1} 1/(1 + x^k)^(sigma_2(k)).
%H A288422 Seiichi Manyama, <a href="/A288422/b288422.txt">Table of n, a(n) for n = 0..10000</a>
%F A288422 Convolution inverse of A288414.
%F A288422 a(0) = 1, a(n) = -(1/n)*Sum_{k=1..n} A288419(k)*a(n-k) for n > 0.
%F A288422 G.f.: exp(-Sum_{k>=1} sigma_3(k)*x^k/(k*(1 - x^(2*k)))). - _Ilya Gutkovskiy_, Oct 29 2018
%t A288422 nmax = 40; CoefficientList[Series[Product[1/(1+x^k)^DivisorSigma[2, k], {k, 1, nmax}], {x, 0, nmax}], x] (* _Vaclav Kotesovec_, Jun 09 2017 *)
%o A288422 (PARI) m=50; x='x+O('x^m); Vec(prod(k=1, m+2, 1/(1+x^k)^sigma(k,2))) \\ _G. C. Greubel_, Oct 29 2018
%o A288422 (Magma) m:=50; R<q>:=PowerSeriesRing(Rationals(), m); Coefficients(R! ( (&*[1/(1+q^k)^DivisorSigma(2,k): k in [1..(m+2)]]) )); // _G. C. Greubel_, Oct 29 2018
%Y A288422 Cf. A288414, A288419.
%Y A288422 Product_{k>=1} 1/(1 + x^k)^sigma_m(k): A288007 (m=0), A288421 (m=1), this sequence (m=2), A288423 (m=3).
%K A288422 sign
%O A288422 0,3
%A A288422 _Seiichi Manyama_, Jun 09 2017