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 A111555 #3 Mar 30 2012 18:36:50
%S A111555 1,3,16,116,1016,10176,113216,1375456,18047296,253815936,3805221376,
%T A111555 60558070016,1019617312256,18111737604096,338602832961536,
%U A111555 6648048064792576,136810876329865216,2945671077411987456
%N A111555 Column 2 of triangle A111553.
%o A111555 (PARI) {a(n)=if(n<0,0,(matrix(n+3,n+3,m,j,if(m==j,1,if(m==j+1,-m+1, -(m-j-1)*polcoeff(log(sum(i=0,m,(i+3)!/3!*x^i)),m-j-1))))^-1)[n+3,3])}
%Y A111555 Cf. A111553, A111531.
%K A111555 nonn
%O A111555 0,2
%A A111555 _Paul D. Hanna_, Aug 07 2005