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 A327799 #4 Sep 25 2019 20:33:59
%S A327799 1,-1,0,0,-1,2,-2,2,-1,-2,5,-6,5,-1,-5,10,-14,14,-5,-10,26,-38,36,-15,
%T A327799 -20,60,-91,93,-51,-33,138,-223,237,-145,-52,307,-528,596,-412,-43,
%U A327799 674,-1258,1492,-1126,84,1442,-2938,3687,-3034,680,3000,-6818,9050,-7997
%N A327799 Expansion of 1 / (1 + Sum_{i>=1} Sum_{j=1..i} x^(i*j)).
%F A327799 G.f.: 1 / (1 + Sum_{k>=1} x^(k^2) / (1 - x^k)).
%F A327799 a(0) = 1; a(n) = -Sum_{k=1..n} A038548(k) * a(n-k).
%t A327799 nmax = 53; CoefficientList[Series[1/(1 + Sum[x^(k^2)/(1 - x^k), {k, 1, nmax}]), {x, 0, nmax}], x]
%t A327799 a[0] = 1; a[n_] := a[n] = -Sum[Floor[(DivisorSigma[0, k] + 1)/2] a[n - k], {k, 1, n}]; Table[a[n], {n, 0, 53}]
%Y A327799 Cf. A038548, A159933, A327739.
%K A327799 sign
%O A327799 0,6
%A A327799 _Ilya Gutkovskiy_, Sep 25 2019