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 A343190 #4 Apr 07 2021 19:56:15
%S A343190 1,1,1,1,1,1,0,0,0,0,0,-1,-1,-1,-1,-1,-2,-2,-1,-2,-1,-3,-2,-2,-2,-1,
%T A343190 -3,-3,0,-3,0,-3,-2,-1,-1,-1,-2,-2,1,-1,3,-3,-1,2,2,2,-1,-2,5,4,4,-2,
%U A343190 1,5,7,6,-1,0,10,7,10,0,0,9,14,9,0,2,12,15,14,-1,3,14,18
%N A343190 a(1) = ... = a(5) = 1; a(n+5) = Sum_{d|n} mu(n/d) * a(d).
%t A343190 a[1] = a[2] = a[3] = a[4] = a[5] = 1; a[n_] := a[n] = Sum[MoebiusMu[(n - 5)/d] a[d], {d, Divisors[n - 5]}]; Table[a[n], {n, 75}]
%Y A343190 Cf. A007554, A307995, A318583, A343188, A343189.
%K A343190 sign
%O A343190 1,17
%A A343190 _Ilya Gutkovskiy_, Apr 07 2021