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 A357521 #6 Oct 02 2022 10:29:08
%S A357521 1,-1,1,0,-1,2,-3,3,-2,0,1,-2,2,-2,1,-2,3,-4,4,-2,0,2,-5,6,-5,3,-2,1,
%T A357521 -1,1,0,0,3,-6,6,-5,4,0,-5,7,-7,5,-2,2,0,-2,0,1,5,-7,11,-14,11,-6,-1,
%U A357521 9,-12,8,-11,11,-6,10,-13,8,-2,-12,26,-26,24,-20,2,11,-8,14,-15,9
%N A357521 Expansion of Product_{k>=1} (1 - mu(k)*x^k).
%t A357521 nmax = 75; CoefficientList[Series[Product[(1 - MoebiusMu[k] x^k), {k, 1, nmax}], {x, 0, nmax}], x]
%t A357521 a[0] = 1; a[n_] := a[n] = -(1/n) Sum[Sum[d MoebiusMu[d]^(k/d), {d, Divisors[k]}] a[n - k], {k, 1, n}]; Table[a[n], {n, 0, 75}]
%Y A357521 Cf. A008683, A117208, A185694, A292561, A300663, A306327, A357524, A357525.
%K A357521 sign
%O A357521 0,6
%A A357521 _Ilya Gutkovskiy_, Oct 02 2022