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 A345138 #5 Jun 09 2021 11:14:31
%S A345138 1,0,0,1,1,1,1,1,1,2,1,2,1,3,1,2,2,3,1,3,1,5,2,2,1,6,2,2,2,6,1,6,1,5,
%T A345138 2,3,3,9,1,2,2,9,1,7,1,8,4,3,1,10,2,5,3,9,1,8,3,9,2,3,1,18,1,2,4,11,3,
%U A345138 9,1,9,3,10,1,15,1,4,4,12,3,10,1,13,4,3,1,21,4,2,3,16,1,17,3,12,2
%N A345138 a(1) = 1, a(2) = 0; a(n+2) = Sum_{d|n, d < n} a(d).
%F A345138 G.f. A(x) satisfies: A(x) = x + x^2 *(A(x^2) + A(x^3) + A(x^4) + ...).
%t A345138 a[1] = 1; a[2] = 0; a[n_] := a[n] = Sum[If[d < n - 2, a[d], 0], {d, Divisors[n - 2]}]; Table[a[n], {n, 1, 95}]
%t A345138 nmax = 95; A[_] = 0; Do[A[x_] = x + x^2 Sum[A[x^k], {k, 2, nmax}] + O[x]^(nmax + 1) // Normal, nmax + 1]; CoefficientList[A[x], x] // Rest
%Y A345138 Cf. A007439, A074206, A167865, A345137, A345141.
%K A345138 nonn
%O A345138 1,10
%A A345138 _Ilya Gutkovskiy_, Jun 09 2021