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 A386443 #10 Jul 22 2025 09:52:07
%S A386443 1,1,2,11,120,2166,58642,2231959,113926332,7522541374,624529876412,
%T A386443 63711767096254,7837308575551868,1144321503810951264,
%U A386443 195687862794184808186,38747465910056072904383,8795888226933223095245628,2269380895962602685279019270,660399219910352767447886420340
%N A386443 a(0) = 1; a(n) = a(n-1) + Sum_{k=0..n-1} k^2 * a(k) * a(n-1-k).
%F A386443 G.f. A(x) satisfies A(x) = 1/( 1 - x - x^2 * (d/dx A(x)) - x^3 * (d^2/dx^2 A(x)) ).
%o A386443 (PARI) a_vector(n) = my(v=vector(n+1)); v[1]=1; for(i=1, n, v[i+1]=v[i]+sum(j=0, i-1, j^2*v[j+1]*v[i-j])); v;
%Y A386443 Cf. A075834, A386444, A386445, A386446, A386447.
%Y A386443 Cf. A385830, A386448, A386452.
%K A386443 nonn
%O A386443 0,3
%A A386443 _Seiichi Manyama_, Jul 22 2025