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 A320777 #6 Oct 22 2018 17:42:49
%S A320777 1,0,1,1,0,0,0,0,-1,-1,1,1,0,-1,0,1,-1,-2,1,3,1,-2,-2,1,0,-4,0,6,6,-4,
%T A320777 -8,1,4,-4,-5,10,16,-4,-25,-7,17,5,-16,2,42,12,-58,-48,40,59,-27,-44,
%U A320777 67,86,-103,-187,36,236,45,-213,-5,284,-23,-526,-188,663,520
%N A320777 Inverse Euler transform of the number of distinct prime factors (without multiplicity) function A001221.
%C A320777 The Euler transform of a sequence q is the sequence of coefficients of x^n, n > 0, in the expansion of Product_{n > 0} 1/(1 - x^n)^q(n). The constant term 1 is sometimes taken to be the zeroth part of the Euler transform.
%t A320777 EulerInvTransform[{}]={};EulerInvTransform[seq_]:=Module[{final={}},For[i=1,i<=Length[seq],i++,AppendTo[final,i*seq[[i]]-Sum[final[[d]]*seq[[i-d]],{d,i-1}]]];
%t A320777 Table[Sum[MoebiusMu[i/d]*final[[d]],{d,Divisors[i]}]/i,{i,Length[seq]}]];
%t A320777 EulerInvTransform[Array[PrimeNu,100]]
%Y A320777 Number theoretical functions: A000005, A000010, A000203, A001055, A001221, A001222, A008683, A010054.
%Y A320777 Euler transforms: A000081, A001970, A006171, A007294, A061255, A061256, A061257, A073576, A117209, A293548, A293549.
%Y A320777 Inverse Euler transforms: A059966, A320767, A320776, A320778, A320779, A320780, A320781, A320782.
%K A320777 sign
%O A320777 0,18
%A A320777 _Gus Wiseman_, Oct 22 2018