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 A328731 #4 Oct 26 2019 15:34:19
%S A328731 1,-2,-3,-1,-5,0,-7,-4,-3,0,-11,3,-13,0,0,3,-17,6,-19,5,0,0,-23,18,
%T A328731 -10,0,-10,7,-29,30,-31,-2,0,0,0,24,-37,0,0,30,-41,42,-43,11,15,0,-47,
%U A328731 27,-21,20,0,13,-53,38,0,42,0,0,-59,60,-61,0,21,17,0,66,-67,17,0,70
%N A328731 Dirichlet g.f.: Product_{k>=2} 1 / (1 + k^(-s))^k.
%C A328731 Dirichlet inverse of A050368.
%F A328731 a(1) = 1; a(n) = -Sum_{d|n, d<n} A050368(n/d) * a(d).
%Y A328731 Cf. A006881 (positions of 0's), A050368, A316441, A328730.
%K A328731 sign
%O A328731 1,2
%A A328731 _Ilya Gutkovskiy_, Oct 26 2019