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 A327800 #4 Sep 25 2019 20:34:06
%S A327800 1,0,-1,-1,0,1,0,0,1,1,-2,-3,0,4,2,-3,0,4,-1,-10,-5,12,13,-6,-12,7,9,
%T A327800 -20,-28,23,57,1,-59,-18,51,-5,-93,1,176,93,-189,-188,131,183,-191,
%U A327800 -220,370,525,-347,-902,44,973,64,-1071,171,1881,156,-2974,-1537
%N A327800 Expansion of 1 / (1 + Sum_{i>=1, j>=1} x^(i*prime(j))).
%F A327800 G.f.: 1 / (1 + Sum_{k>=1} x^prime(k) / (1 - x^prime(k))).
%F A327800 a(0) = 1; a(n) = -Sum_{k=1..n} A001221(k) * a(n-k).
%t A327800 nmax = 58; CoefficientList[Series[1/(1 + Sum[x^Prime[k]/(1 - x^Prime[k]), {k, 1, nmax}]), {x, 0, nmax}], x]
%t A327800 a[0] = 1; a[n_] := a[n] = -Sum[PrimeNu[k] a[n - k], {k, 1, n}]; Table[a[n], {n, 0, 58}]
%Y A327800 Cf. A001221, A300671.
%K A327800 sign
%O A327800 0,11
%A A327800 _Ilya Gutkovskiy_, Sep 25 2019