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 A385939 #9 Jul 13 2025 11:05:25
%S A385939 1,1,5,88,3893,352536,57322537,15277686880,6239711818377,
%T A385939 3708478187297920,3079046917046731661,3455392385954013825024,
%U A385939 5100835934217411940938685,9682263835381845999967986688,23180826149963609282826172967025,68850271609123855250628849758027776
%N A385939 a(0) = 1; a(n) = Sum_{k=0..n-1} (1 + k) * (1 + k^2) * binomial(n-1,k) * a(k) * a(n-1-k).
%F A385939 E.g.f. A(x) satisfies A(x) = exp( x * A(x) + x^2 * (d/dx A(x)) + x^3 * (d^2/dx^2 A(x)) ).
%o A385939 (PARI) a_vector(n) = my(v=vector(n+1)); v[1]=1; for(i=1, n, v[i+1]=sum(j=0, i-1, (1+j)*(1+j^2)*binomial(i-1, j)*v[j+1]*v[i-j])); v;
%Y A385939 Cf. A156326, A385940, A385941, A385942, A385943.
%Y A385939 Cf. A385830.
%K A385939 nonn
%O A385939 0,3
%A A385939 _Seiichi Manyama_, Jul 13 2025