A347679 Irregular triangle read by rows: T(n,k) (1 <= k <= 2*n) = number of n X k Baxter matrices in which all row sums are 2.

0, 1, 0, 0, 2, 4, 0, 0, 0, 3, 24, 26, 0, 0, 0, 0, 8, 98, 284, 214, 0, 0, 0, 0, 0, 19, 374, 1922, 3496, 2030, 0, 0, 0, 0, 0, 0, 44, 1342, 10620, 33398, 44674, 21174, 0, 0, 0, 0, 0, 0, 0, 111, 4596, 51904, 245684, 554500, 589092, 236410

Offset: 1

Author

N. J. A. Sloane, Sep 10 2021

Keywords

• nonn
• tabf
• more

Examples

			The T(4,5)=8 matrices of size 4 X 5 are
.
  0 0 0 1 1   0 0 0 1 1   0 1 0 0 1   1 0 0 0 1
  0 0 1 1 0   1 0 0 1 0   0 0 1 1 0   0 0 1 1 0
  0 1 1 0 0   0 1 1 0 0   0 1 0 0 1   0 1 1 0 0
  1 1 0 0 0   1 0 0 1 0   1 1 0 0 0   1 0 0 0 1
.
  1 0 0 0 1   1 0 0 1 0   1 1 0 0 0   1 1 0 0 0
  0 1 1 0 0   0 1 1 0 0   0 1 0 0 1   0 1 1 0 0
  0 0 1 1 0   1 0 0 1 0   0 0 1 1 0   0 0 1 1 0
  1 0 0 0 1   0 0 0 1 1   0 1 0 0 1   0 0 0 1 1
		

Links

• Don Knuth, Baxter matrices, Preprint, Sep 05 2021.

Crossrefs

Cf. A347678, A347736 (superdiagonal).