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 A132618 #2 Mar 30 2012 18:37:04
%S A132618 1,1,5,56,1020,26015,855478,34461260,1642995124,90456911140,
%T A132618 5646312067585,393937815588880,30374808071994000,2564601377235725520,
%U A132618 235302361169390146650,23309583579201438877060
%N A132618 Column 2 of triangle A132615.
%C A132618 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.
%o A132618 (PARI) {a(n)=local(A=vector(n+1), p); A[1]=1; for(j=1, n-1, p=(n+1)*n-(n-j+1)*(n-j); A=Vec((Polrev(A)+x*O(x^p))/(1-x))); A=Vec((Polrev(A)+x*O(x^p))/(1-x)); A[p+1]}
%Y A132618 Cf. A132615 (triangle); other columns: A132616, A132617; A132619.
%K A132618 nonn
%O A132618 0,3
%A A132618 _Paul D. Hanna_, Aug 24 2007