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 A374076 #6 Jun 28 2024 14:01:21
%S A374076 1,0,0,0,-1,0,0,0,1,-1,0,0,-1,1,-1,0,1,-1,2,-1,-1,1,-2,2,0,-1,2,-3,2,
%T A374076 0,-2,3,-3,2,1,-3,4,-4,2,2,-4,5,-5,1,3,-6,7,-5,1,5,-8,8,-6,-1,8,-10,
%U A374076 11,-6,-3,10,-14,12,-5,-6,15,-17,14,-4,-10,19,-21,15,-1,-15,25,-25
%N A374076 Expansion of Product_{k>=1} 1 / (1 + x^(5*k-1)).
%t A374076 nmax = 75; CoefficientList[Series[Product[1/(1 + x^(5 k - 1)), {k, 1, nmax}], {x, 0, nmax}], x]
%t A374076 a[0] = 1; a[n_] := a[n] = (1/n) Sum[DivisorSum[k, (-1)^(k/#) # &, Mod[#, 5] == 4 &] a[n - k], {k, 1, n}]; Table[a[n], {n, 0, 75}]
%Y A374076 Cf. A081360, A081362, A109700, A281243, A284317, A374064, A374065, A374077, A374078, A374079.
%K A374076 sign
%O A374076 0,19
%A A374076 _Ilya Gutkovskiy_, Jun 27 2024