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 A102922 #4 Mar 30 2012 18:36:44 %S A102922 0,4,40,1128,61120,5466320,735847800,139910204080,35858685086352, %T A102922 11953187179149408,5037776918810353960,2623732639426967662648, %U A102922 1656984556235159516822400,1248959074762601252295551168 %N A102922 Column 1 of triangle A102920, which equals the matrix square of A102098. %C A102922 Equals the odd bisection of A102917. Triangle A102098 shifts each column up 1 row under matrix cube. %o A102922 (PARI) {a(n)=local(A=matrix(2,2),B);A[1,1]=1; for (m=2,n+1,B=matrix(m,m);for (i=1,m, for (j=1,i, if(j==i,B[i,j]=j,if(j==1,B[i,j]=(A^3)[i-1,1], B[i,j]=(A^3)[i-1,j]));));A=B);return((A^2)[n+1,2])} %Y A102922 Cf. A102920, A102098, A102917. %K A102922 nonn %O A102922 0,2 %A A102922 _Paul D. Hanna_, Jan 21 2005