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 A386455 #8 Jul 22 2025 09:51:26
%S A386455 1,1,2,15,344,19962,2555592,649147331,301207446317,239159429472132,
%T A386455 308276821981867349,617786997525975886618,1856450241316927094671750,
%U A386455 8112688179283378712969957414,50217541700003149682333160103969,430364340522944093019900101527085125
%N A386455 a(0) = 1; a(n) = a(n-1) + Sum_{k=0..n-1} binomial(k+4,5) * a(k) * a(n-1-k).
%F A386455 G.f. A(x) satisfies A(x) = 1/( 1 - x - x*Sum_{k=1..5} binomial(4,k-1) * x^k/k! * (d^k/dx^k A(x)) ).
%o A386455 (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, binomial(j+4, 5)*v[j+1]*v[i-j])); v;
%Y A386455 Cf. A075834, A386452, A386453, A386454.
%Y A386455 Cf. A385877.
%K A386455 nonn
%O A386455 0,3
%A A386455 _Seiichi Manyama_, Jul 22 2025