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 A329438 #4 Nov 13 2019 15:09:36
%S A329438 0,1,1,1,2,2,2,2,2,5,1,4,2,5,5,5,2,7,3,9,7,6,5,10,7,9,7,11,7,14,9,12,
%T A329438 11,12,13,20,11,15,16,22,14,25,15,23,22,24,19,33,23,33,25,34,26,39,33,
%U A329438 41,36,40,35,57,39,50,50,56,49,66,50,65,61,75,61
%N A329438 Expansion of Sum_{k>=1} (-1 + Product_{j>=1} (1 + x^(k*prime(j)))).
%C A329438 Inverse Moebius transform of A000586.
%F A329438 G.f.: Sum_{k>=1} A000586(k) * x^k / (1 - x^k).
%F A329438 a(n) = Sum_{d|n} A000586(d).
%t A329438 nmax = 71; CoefficientList[Series[Sum[-1 + Product[(1 + x^(k Prime[j])), {j, 1, nmax}], {k, 1, nmax}], {x, 0, nmax}], x] // Rest
%Y A329438 Cf. A000586, A047966, A047968, A329437.
%K A329438 nonn
%O A329438 1,5
%A A329438 _Ilya Gutkovskiy_, Nov 13 2019