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 A111550 #3 Mar 30 2012 18:36:50
%S A111550 0,2,6,32,222,1824,17016,176112,1993392,24438960,322294896,4548010032,
%T A111550 68385367152,1091838106800,18454096189296,329306074785072,
%U A111550 6189015238217712,122232512688657840,2531600753529542256
%N A111550 Column 1 of A111549, which is the matrix log of A111544.
%o A111550 (PARI) {a(n)=local(M=matrix(n+2,n+2,m,j,if(m==j,1,if(m==j+1,-m+1, -(m-j-1)*polcoeff(log(sum(i=0,m,(i+2)!/2!*x^i)),m-j-1))))); if(n<0,0,sum(i=1,#M,(M^0-M)^i/i)[n+2,2])}
%Y A111550 Cf. A111549, A111544.
%K A111550 nonn
%O A111550 0,2
%A A111550 _Paul D. Hanna_, Aug 07 2005