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 A124549 #5 Jun 14 2017 00:13:16
%S A124549 1,1,5,39,399,4943,70846,1142543,20355695,395414964,8292073877,
%T A124549 186265497096,4453789285009,112771923093955,3010597702761965,
%U A124549 84424863975107571,2478907364772699611,75998810193380960765
%N A124549 Derived from a diagonal of rectangular table A124540: a(n) = A124540(n+1,n)/(n+1).
%C A124549 In table A124540, the g.f. of row n, R_n(y), simultaneously satisfies: R_n(y) = [ Sum_{k>=0} y^k*R_k(y)^n ]^n for n>=0.
%F A124549 a(n) = A124548(n)/(n+1).
%o A124549 (PARI) a(n)=local(R);R=vector(n+2,r,vector(n+2,c,if(r==1 || c<=2,1,r^(c-2)))); for(i=0,n+1,for(r=0,n+1,R[r+1]=Vec(sum(c=0,n,x^c*Ser(R[c+1])^(r*c)+O(x^(n+2)))))); Vec(Ser(R[n+2])^(n+1)+O(x^(n+2)))[n+1]/(n+1)
%Y A124549 Cf. A124540, A124548, A124547.
%K A124549 nonn
%O A124549 0,3
%A A124549 _Paul D. Hanna_, Nov 05 2006