A104716 Triangle T(n,k) = (2k-3+4n)*(k-1-n)*(k-2-n)/6, 1<=k<=n.

1, 7, 3, 22, 13, 5, 50, 34, 19, 7, 95, 70, 46, 25, 9, 161, 125, 90, 58, 31, 11, 252, 203, 155, 110, 70, 37, 13, 372, 308, 245, 185, 130, 82, 43, 15, 525, 444, 364, 287, 215, 150, 94, 49, 17, 715, 615, 516, 420, 329, 245, 170, 106, 55, 19, 946, 825, 705, 588, 476, 371, 275, 190, 118, 61, 21

Offset: 1

Author

Gary W. Adamson, Mar 20 2005

Keywords

• nonn
• tabl
• easy

Comments

The triangle is created by the matrix product A158405 * A004736, regarding both as infinite lower triangular matrices, rest of the terms filled in with zeros.

Apparently, row n contains the initial terms of row 2n-2 of A177877. - R. J. Mathar, Aug 31 2011

Examples

			First few rows are:
1;
7, 3;
22, 13, 5;
50, 34, 19, 7;
95, 70, 46, 25, 9;
...
		

Crossrefs

Cf. A104715, A002419 (row sums).

Programs

Maple

A104716 := proc(n,k) (2*k-3+4*n)*(k-1-n)*(k-2-n)/6 ; end proc:
seq(seq(A104716(n,k),k=1..n),n=1..15) ; # R. J. Mathar, Aug 31 2011

Extensions

Closed-form definition by R. J. Mathar, Aug 31 2011