A113384 Triangle, read by rows, equal to the matrix square of A113381. Also given by: Q^2 = R*P = R*Q*(R^-2)*Q*R = P*Q*(P^-2)*Q*P, using triangular matrices P=A113370, Q=A113381 and R=A113389.
1, 4, 1, 22, 10, 1, 212, 130, 16, 1, 3255, 2365, 328, 22, 1, 70777, 57695, 8640, 616, 28, 1, 2022897, 1798275, 284356, 21197, 994, 34, 1, 72375484, 68931064, 11358500, 875424, 42196, 1462, 40, 1, 3130502129, 3155772612, 537277044, 42499204
Offset: 0
Examples
Triangle A113381^2 begins: 1; 4,1; 22,10,1; 212,130,16,1; 3255,2365,328,22,1; 70777,57695,8640,616,28,1; 2022897,1798275,284356,21197,994,34,1; 72375484,68931064,11358500,875424,42196,1462,40,1; 3130502129,3155772612,537277044,42499204,2094365,73797,2020,46,1;
Programs
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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-1))[r-c+1,1]))^2)[n+1,k+1]