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 A102920 #4 Mar 30 2012 18:36:44
%S A102920 1,3,4,36,40,9,1036,1128,189,16,56355,61120,9720,576,25,5045370,
%T A102920 5466320,857466,47040,1375,36,679409158,735847800,114915375,6155008,
%U A102920 163500,2808,49,129195427716,139910204080,21813099606,1158059520,29767000,458136
%N A102920 Triangular matrix, read by rows, equal to the matrix square of A102098.
%C A102920 Column 0 is A102921. Column 1 is A102922.
%e A102920 Rows begin:
%e A102920 [1],
%e A102920 [3,4],
%e A102920 [36,40,9],
%e A102920 [1036,1128,189,16],
%e A102920 [56355,61120,9720,576,25],
%e A102920 [5045370,5466320,857466,47040,1375,36],
%e A102920 [679409158,735847800,114915375,6155008,163500,2808,49],...
%o A102920 (PARI) {T(n,k)=local(A=matrix(1,1),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,B[i,j]=(A^3)[i-1,j]);));A=B); return((A^2)[n+1,k+1])}
%Y A102920 Cf. A102098, A102921, A102922, A102916.
%K A102920 nonn,tabl
%O A102920 0,2
%A A102920 _Paul D. Hanna_, Jan 21 2005