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 A166908 #2 Mar 30 2012 18:37:18
%S A166908 1,16,270,5148,110929,2677008,71648322,2107966432,67649839664,
%T A166908 2352412120760,88122951915388,3538364803586104,151611580761978784,
%U A166908 6905283671128114400,333151832685664811338,16973306740660778801468
%N A166908 Column 3 of triangle A166905.
%C A166908 Triangle A166905 transforms rows into diagonals in the table A158825 of coefficients in successive iterations of x*Catalan(x) (cf. A000108).
%o A166908 (PARI) {a(n)=local(F=x, G=serreverse(x-x^2+O(x^(n+6))), M, N, P, m=n); M=matrix(m+5, m+5, r, c, F=x;for(i=1, r+c-2, F=subst(F, x, G+x*O(x^(m+5)))); polcoeff(F, c)); N=matrix(m+4, m+4, r, c, F=x;for(i=1, r, F=subst(F, x, G+x*O(x^(m+5)))); polcoeff(F, c)); P=matrix(m+4, m+4, r, c, M[r+1, c]); (P~*N~^-1)[n+4, 4]}
%Y A166908 Cf. A166905, A158831, A166906, A166907, A166909.
%K A166908 nonn
%O A166908 0,2
%A A166908 _Paul D. Hanna_, Nov 28 2009