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%I #5 Jun 13 2017 23:21:08
%S 1,7,91,1722,43764,1415799,56096733,2644883675,145131435225,
%T 9107198292451,644373208531066,50814103000624929,4423148359685316443,
%U 421540670702940409866,43680252604560889074884
%N Column 2 of triangle A113370, also equals column 0 of A113370^7.
%C Column k of A113370 = column 0 of A113370^(3*k+1) for k>=0.
%o (PARI) a(n)=local(A,B);A=Mat(1);for(m=2,n+3,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[n+3,3]
%Y Cf. A113370, A113371 (column 1), A113373 (column 3).
%K nonn
%O 0,2
%A _Paul D. Hanna_, Nov 13 2005
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