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 A124559 #3 Mar 30 2012 18:37:01
%S A124559 1,1,5,51,869,22202,803053,39901447,2677520438,239963727089,
%T A124559 28509710041427,4469877880908109,921904263806801157,
%U A124559 249426774472230102453,88324099839785869552329
%N A124559 Derived from secondary diagonal of table A124550; a(n) = A124550(n+1,n)/(n+1).
%C A124559 In table A124550, the g.f. of row n, R_n(y), simultaneously satisfies: R_n(y) = [ Sum_{k>=0} y^k * R_{n*k}(y) ]^n for n>=0.
%F A124559 a(n) = (n+1)*A124558(n).
%Y A124559 Cf. A124550 (table); A124557, A124558; A124551, A124552, A124554, A124555, A124556.
%K A124559 nonn
%O A124559 0,3
%A A124559 _Paul D. Hanna_, Nov 07 2006