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 A329097 #4 Nov 05 2019 01:02:01
%S A329097 1,0,-1,-1,0,0,1,0,0,-1,1,0,1,-1,1,-1,1,-2,2,-2,2,-2,3,-4,3,-4,5,-5,6,
%T A329097 -6,7,-8,9,-9,11,-12,13,-16,15,-17,20,-22,23,-26,29,-30,35,-38,40,-45,
%U A329097 50,-52,58,-65,69,-75,82,-89,96,-107,114,-123,135,-145,158,-170,185,-200,216,-232,251
%N A329097 Expansion of Product_{p prime, k>=1} 1 / (1 + x^(p^k)).
%C A329097 Convolution inverse of A054685.
%F A329097 G.f.: Product_{k>=1} 1 / (1 + x^A246655(k)).
%t A329097 nmax = 70; CoefficientList[Series[Product[1/(1 + Boole[PrimePowerQ[k]] x^k), {k, 1, nmax}], {x, 0, nmax}], x]
%t A329097 a[n_] := a[n] = If[n == 0, 1, Sum[Sum[(-1)^(k/d) Boole[PrimePowerQ[d]] d, {d, Divisors[k]}] a[n - k], {k, 1, n}]/n]; Table[a[n], {n, 0, 70}]
%Y A329097 Cf. A023894, A048165, A054685, A246655, A328556.
%K A329097 sign
%O A329097 0,18
%A A329097 _Ilya Gutkovskiy_, Nov 04 2019