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 A113376 #5 Jun 13 2017 23:23:13 %S A113376 1,8,84,1296,27850,784146,27630378,1177691946,59169833470, %T A113376 3434258845248,226594550768662,16775755397765720,1378646430074005827, %U A113376 124636321499378130839,12300850874338422058685 %N A113376 Column 1 of triangle A113374, also equals column 0 of A113381^4. %F A113376 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 A113376 (PARI) a(n)=local(A,B);A=Mat(1);for(m=2,n+2,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+2,2] %Y A113376 Cf. A113374, A113375 (column 0), A113377 (column 2). %K A113376 nonn %O A113376 0,2 %A A113376 _Paul D. Hanna_, Nov 14 2005