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 A113093 #3 Mar 30 2012 18:36:51
%S A113093 1,1,13,693,146821,124626530,426524622399,5893207147435867,
%T A113093 328422072384464274577,73719657441008064407836359,
%U A113093 66567306698774377126527799872190
%N A113093 Main diagonal of square table A113092; also, a(n) equals the n-th term in column 0 of the matrix n-th power of triangle A113095.
%o A113093 (PARI) {a(n,q=4)=local(M=matrix(n+1,n+1));for(r=1,n+1, for(c=1,r, M[r,c]=if(r==c,1,if(c>1,(M^q)[r-1,c-1])+(M^q)[r-1,c]))); return((M^n)[n+1,1])}
%Y A113093 Cf. A113092, A113095.
%K A113093 nonn
%O A113093 0,3
%A A113093 _Paul D. Hanna_, Oct 14 2005