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 A113394 #5 Jun 13 2017 23:30:37 %S A113394 1,9,1,99,18,1,1569,360,27,1,34344,9051,783,36,1,980487,284148,26820, %T A113394 1368,45,1,34930455,10865358,1089126,59250,2115,54,1,1502349459, %U A113394 494019714,51784137,2946456,110715,3024,63,1,76058669082,26168502684 %N A113394 Triangle, read by rows, equal to the matrix cube of triangle A113389. %F A113394 Column k of A113389^3 = column 0 of A113389^(3*k+3) for k>=0. %e A113394 Triangle A113389^3 begins: %e A113394 1; %e A113394 9,1; %e A113394 99,18,1; %e A113394 1569,360,27,1; %e A113394 34344,9051,783,36,1; %e A113394 980487,284148,26820,1368,45,1; %e A113394 34930455,10865358,1089126,59250,2115,54,1; %e A113394 1502349459,494019714,51784137,2946456,110715,3024,63,1; %e A113394 76058669082,26168502684,2840586075,167137110,6510780,185589,4095,72,1; %o A113394 (PARI) T(n,k)=local(A,B);A=Mat(1);for(m=2,n+1,B=matrix(m,m); for(i=1,m, for(j=1,i,if(i<3 || j==i || j>m-1,B[i,j]=1,if(j==1, B[i,1]=1,B[i,j]=(A^(3*j-2))[i-j+1,1]));));A=B); (matrix(#A,#A,r,c,if(r>=c,(A^(3*c))[r-c+1,1]))^3)[n+1,k+1] %Y A113394 Cf. A113389, A113395 (column 0); recurrence: A091351, A113355. %K A113394 nonn,tabl %O A113394 0,2 %A A113394 _Paul D. Hanna_, Nov 14 2005