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 A111842 #4 Mar 30 2012 18:36:50
%S A111842 1,2,7,46,595,16444,1048303,162728110,63746277967,64594795730680,
%T A111842 172419318632651104,1229463017642626881490,23684690483668583872503679,
%U A111842 1244115601652916934000237966330,179585081405174505374545193721101377
%N A111842 Row sums of triangle A111840, which shifts columns left and up under matrix cube.
%o A111842 (PARI) {a(n,q=3)=local(A=Mat(1),B);if(n<0,0, for(m=1,n+2,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 A111842 Cf. A111840, A078125 (variant).
%K A111842 nonn
%O A111842 0,2
%A A111842 _Paul D. Hanna_, Aug 23 2005