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 A363468 #6 Jun 03 2023 14:22:34
%S A363468 1,1,1,4,14,48,201,812,3455,14961,65954,294884,1334526,6098879,
%T A363468 28114885,130561444,610244889,2868547475,13552299256,64316483918,
%U A363468 306473091394,1465727378317,7033293786125,33851816310445,163384902125185,790589562321385,3834540111072545,18638976010097900
%N A363468 G.f. A(x) satisfies: A(x) = x + x^2 * exp( Sum_{k>=1} (-1)^(k+1) * A(x^k)^4 / (k*x^(3*k)) ).
%t A363468 nmax = 28; A[_] = 0; Do[A[x_] = x + x^2 Exp[Sum[(-1)^(k + 1) A[x^k]^4/(k x^(3 k)), {k, 1, nmax}]] + O[x]^(nmax + 1)//Normal, nmax + 1]; CoefficientList[A[x], x] // Rest
%t A363468 a[1] = a[2] = 1; f[n_] := f[n] = Sum[a[k] a[n - k], {k, 1, n - 1}]; g[n_] := g[n] = Sum[f[k] f[n - k], {k, 1, n - 1}]; a[n_] := a[n] = (1/(n - 2)) Sum[Sum[(-1)^(k/d + 1)d g[d + 3], {d, Divisors[k]}] a[n - k], {k, 1, n - 2}]; Table[a[n], {n, 1, 28}]
%Y A363468 Cf. A007560, A052775, A363388, A363466, A363467.
%K A363468 nonn
%O A363468 1,4
%A A363468 _Ilya Gutkovskiy_, Jun 03 2023