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 A132617 #2 Mar 30 2012 18:37:04
%S A132617 1,1,3,25,378,8460,252087,9392890,420142350,21927528948,1307723670020,
%T A132617 87712176219801,6534001434836758,535159878432210000,
%U A132617 47792303301224799288,4621416976280491118910,481020078381722064175750
%N A132617 Column 1 of triangle A132615.
%C A132617 Triangle T=A132615 is generated by odd matrix powers of itself such that row n+1 of T = row n of T^(2n-1) with appended '1' for n>=0 with T(0,0)=1.
%F A132617 a(n) is divisible by 2n-1 for n>0; a(n)/(2n-1) = A132619(n).
%o A132617 (PARI) {a(n)=local(A=vector(n+1), p); A[1]=1; for(j=1, n-1, p=n*(n-1)-(n-j)*(n-j-1); A=Vec((Polrev(A)+x*O(x^p))/(1-x))); A=Vec((Polrev(A)+x*O(x^p))/(1-x)); A[p+1]}
%Y A132617 Cf. A132615 (triangle); other columns: A132616, A132618; A132619.
%K A132617 nonn
%O A132617 0,3
%A A132617 _Paul D. Hanna_, Aug 24 2007