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 A327746 #9 Apr 23 2025 17:15:50
%S A327746 1,1,0,2,2,2,3,3,6,7,8,9,14,16,17,26,30,35,43,52,62,77,87,104,133,152,
%T A327746 173,212,251,287,344,397,465,549,627,729,864,986,1127,1325,1524,1740,
%U A327746 2009,2306,2641,3047,3455,3942,4549,5157,5846,6700,7605,8608
%N A327746 Expansion of Product_{i>=1, j>=1} 1 / (1 + (-x)^(i*(2*j - 1))).
%H A327746 Jason Bard, <a href="/A327746/b327746.txt">Table of n, a(n) for n = 0..2000</a>
%F A327746 G.f.: Product_{k>=1} 1 / (1 + (-x)^k)^A001227(k).
%t A327746 nmax = 53; CoefficientList[Series[Product[1/(1 + (-x)^k)^DivisorSum[k, Mod[#, 2] &], {k, 1, nmax}], {x, 0, nmax}], x]
%t A327746 a[n_] := a[n] = If[n == 0, 1, Sum[(-1)^k Sum[(-1)^(k/d) d DivisorSum[d, Mod[#, 2] &], {d, Divisors[k]}] a[n - k], {k, 1, n}]/n]; Table[a[n], {n, 0, 53}]
%Y A327746 Cf. A001227, A107742, A288007, A327731.
%K A327746 nonn
%O A327746 0,4
%A A327746 _Ilya Gutkovskiy_, Sep 23 2019