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 A288423 #27 Sep 08 2022 08:46:19
%S A288423 1,-1,-8,-20,-8,134,512,1062,406,-5319,-22532,-51843,-58869,83035,
%T A288423 648412,1947384,3665081,3040131,-8272126,-46481039,-128400098,
%U A288423 -234847560,-215189896,378947363,2437661943,7036096665,13868464378,16886982518,-4042283985,-93095770772
%N A288423 Expansion of Product_{k>=1} 1/(1 + x^k)^(sigma_3(k)).
%H A288423 Seiichi Manyama, <a href="/A288423/b288423.txt">Table of n, a(n) for n = 0..7039</a>
%F A288423 Convolution inverse of A288415.
%F A288423 a(0) = 1, a(n) = -(1/n)*Sum_{k=1..n} A288420(k)*a(n-k) for n > 0.
%F A288423 G.f.: exp(-Sum_{k>=1} sigma_4(k)*x^k/(k*(1 - x^(2*k)))). - _Ilya Gutkovskiy_, Oct 29 2018
%p A288423 with(numtheory): seq(coeff(series(mul(1/(1+x^k)^(sigma[3](k)),k=1..n),x,n+1), x, n), n = 0 .. 30); # _Muniru A Asiru_, Oct 31 2018
%t A288423 nmax = 40; CoefficientList[Series[Product[1/(1+x^k)^DivisorSigma[3, k], {k, 1, nmax}], {x, 0, nmax}], x] (* _Vaclav Kotesovec_, Jun 09 2017 *)
%o A288423 (PARI) m=40; x='x+O('x^m); Vec(prod(k=1, m, 1/(1+x^k)^sigma(k,3))) \\ _G. C. Greubel_, Oct 30 2018
%o A288423 (Magma) m:=40; R<q>:=PowerSeriesRing(Rationals(), m); Coefficients(R! ( (&*[1/(1+q^k)^DivisorSigma(3,k): k in [1..m]]) )); // _G. C. Greubel_, Oct 30 2018
%Y A288423 Cf. A288415, A288420.
%Y A288423 Product_{k>=1} 1/(1 + x^k)^sigma_m(k): A288007 (m=0), A288421 (m=1), A288422 (m=2), this sequence (m=3).
%K A288423 sign
%O A288423 0,3
%A A288423 _Seiichi Manyama_, Jun 09 2017