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 A113375 #5 Jun 13 2017 23:21:06 %S A113375 1,2,6,37,429,7629,185776,5817106,224558216,10362978307,558458382528, %T A113375 34504326965326,2408502186081117,187672037804601000, %U A113375 16162473554575583148,1525578320627987001344,156704538246796929248712 %N A113375 Column 0 of triangle A113374, also equals column 0 of A113381. %F A113375 A113374 equals the matrix square of A113370, which has the property: column k of A113370^2 = column 0 of A113381^(3*k+1) for k>=0. %o A113375 (PARI) a(n)=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);(A^2)[n+1,1] %Y A113375 Cf. A113374, A113376 (column 1), A113377 (column 2). %K A113375 nonn %O A113375 0,2 %A A113375 _Paul D. Hanna_, Nov 14 2005