A113392 Triangle, read by rows, equal to the matrix square of triangle A113389. Also given by the matrix product: R^2 = Q^3*(P^-2)*Q, using triangular matrices P=A113370, Q=A113381 and R=A113389.

1, 6, 1, 48, 12, 1, 605, 186, 18, 1, 11196, 3892, 414, 24, 1, 280440, 106089, 12021, 732, 30, 1, 8981460, 3620379, 429345, 27152, 1140, 36, 1, 353283128, 149740555, 18386361, 1196910, 51445, 1638, 42, 1, 16567072675, 7316974618, 923656512

Offset: 0

Author

Paul D. Hanna, Nov 14 2005

Keywords

• nonn
• tabl

Examples

			Triangle A113389^2 begins:
1;
6,1;
48,12,1;
605,186,18,1;
11196,3892,414,24,1;
280440,106089,12021,732,30,1;
8981460,3620379,429345,27152,1140,36,1;
353283128,149740555,18386361,1196910,51445,1638,42,1;
16567072675,7316974618,923656512,61515702,2696010,87060,2226,48,1;
		

Crossrefs

Cf. A113389, A113388 (column 0), A113393 (column 1).

Programs

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]))^2)[n+1,k+1]