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 A111847 #6 Mar 14 2015 10:03:38
%S A111847 1,2,9,97,2689,214017,53130241,43283609601,119521939222529,
%T A111847 1144341237628100609,38638551719263573098497,
%U A111847 4662529388979590206324834305,2032489532637330252763496597356545
%N A111847 Row sums of triangle A111845, which shifts columns left and up under matrix 4th power.
%o A111847 (PARI) {a(n,q=4)=local(A=Mat(1),B);if(n<0,0, for(m=1,n+1,B=matrix(m,m);for(i=1,m, for(j=1,i, if(j==i,B[i,j]=1,if(j==1,B[i,j]=(A^q)[i-1,1], B[i,j]=(A^q)[i-1,j-1]));));A=B); return(sum(k=0,n,A[n+1,k+1])))}
%Y A111847 Cf. A111845 (triangle), A078537 (variant).
%K A111847 nonn
%O A111847 0,2
%A A111847 _Paul D. Hanna_, Aug 23 2005