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 A319108 #6 Apr 03 2019 02:55:21
%S A319108 1,0,-1,-2,-3,-2,-1,4,8,14,17,18,9,-4,-27,-58,-88,-114,-122,-106,-48,
%T A319108 48,200,376,577,746,862,840,646,208,-486,-1450,-2622,-3888,-5086,
%U A319108 -5950,-6204,-5492,-3547,-44,5036,11732,19582,28034,35932,42042,44519,41660,31450,12382,-16721
%N A319108 Expansion of Product_{k>=1} (1 - x^k)^(k-1).
%C A319108 Convolution of A000041 and A073592.
%C A319108 Convolution inverse of A052847.
%F A319108 G.f.: exp(Sum_{k>=1} (sigma_1(k) - sigma_2(k))*x^k/k), where sigma_1(k) = sum of divisors of k (A000203) and sigma_2(k) = sum of squares of divisors of k (A001157).
%p A319108 a:=series(mul((1-x^k)^(k-1),k=1..100),x=0,51): seq(coeff(a,x,n),n=0..50); # _Paolo P. Lava_, Apr 02 2019
%t A319108 nmax = 50; CoefficientList[Series[Product[(1 - x^k)^(k - 1), {k, 1, nmax}], {x, 0, nmax}], x]
%t A319108 nmax = 50; CoefficientList[Series[Exp[Sum[(DivisorSigma[1, k] - DivisorSigma[2, k]) x^k/k, {k, 1, nmax}]], {x, 0, nmax}], x]
%t A319108 a[n_] := a[n] = If[n == 0, 1, Sum[Sum[d (1 - d), {d, Divisors[k]}] a[n - k], {k, 1, n}]/n]; Table[a[n], {n, 0, 50}]
%Y A319108 Cf. A000041, A000203, A001157, A052847, A073592, A299019.
%K A319108 sign
%O A319108 0,4
%A A319108 _Ilya Gutkovskiy_, Sep 10 2018