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 A354737 #5 Jun 06 2022 02:51:07
%S A354737 1,1,2,6,20,80,336,1568,7584,39312,210080,1180256,6813312,40890304,
%T A354737 251528704,1597332480,10376040448,69259146752,472084038144,
%U A354737 3295588345344,23459477468160,170610216311808,1263629972183040,9543419750909952,73322350509367296,573544008429363200
%N A354737 a(0) = a(1) = 1; a(n) = n * Sum_{k=0..n-2} a(k) * a(n-k-2).
%F A354737 G.f. A(x) satisfies: A(x) = 1 + x + 2 * x^2 * A(x)^2 + 2 * x^3 * A(x) * A'(x).
%t A354737 a[0] = a[1] = 1; a[n_] := a[n] = n Sum[a[k] a[n - k - 2], {k, 0, n - 2}]; Table[a[n], {n, 0, 25}]
%t A354737 nmax = 25; A[_] = 0; Do[A[x_] = 1 + x + 2 x^2 A[x]^2 + 2 x^3 A[x] D[A[x], x] + O[x]^(nmax + 1) // Normal, nmax + 1]; CoefficientList[A[x], x]
%Y A354737 Cf. A000699, A007477, A185183, A354738.
%K A354737 nonn
%O A354737 0,3
%A A354737 _Ilya Gutkovskiy_, Jun 04 2022