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 A124462 #3 Mar 30 2012 18:37:01
%S A124462 1,3,8,23,73,251,919,3549,14371,60720,266481,1209807,5662008,27238884,
%T A124462 134391046,678739990,3503708942,18462855900,99211177417,543161148837,
%U A124462 3027439667989,17167987227428,98995692542858,580166879766649
%N A124462 Row 2 of rectangular table A124460.
%F A124462 G.f.: A(x) = Sum_{n>=0} x^n*R_n(x)^2, where R_n(x) is the g.f. of row n in table A124460 and satisfies: R_n(x) = Sum_{k>=0} x^k * R_k(x)^n for n>=0.
%o A124462 (PARI) {a(n)=local(m=max(n,2),R=vector(m+1,r,vector(m+1,c,binomial(r+c-2,c-1)))); for(i=0,m,for(r=0,m,R[r+1]=Vec(sum(c=0,m,x^c*Ser(R[c+1])^r+O(x^(m+1))))));R[3][n+1]}
%Y A124462 Cf. A124460 (table); other rows: A124461, A124463, A124464, A124465, A124466.
%K A124462 nonn
%O A124462 0,2
%A A124462 _Paul D. Hanna_, Nov 03 2006