A227061 T(n,k) = Number of (n+k-1) X (n+k-1) binary arrays with k 1s in every row and column with rows and columns in lexicographically nondecreasing order.

1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 3, 5, 1, 1, 1, 5, 25, 13, 1, 1, 1, 8, 161, 272, 42, 1, 1, 1, 13, 1112, 7776, 4070, 155, 1, 1, 1, 21, 8787, 287311, 626649, 79221, 636, 1, 1, 1, 34, 76156, 13704640, 137393147, 70821384, 1906501, 2889, 1, 1, 1, 55, 728699, 809171699

Offset: 1

Author

R. H. Hardin Sep 17 2013

Keywords

• nonn
• tabl

Comments

Table starts

.1...1.....1......1......1....1.....1..1.1.1

.1...1.....1......1......1....1.....1..1.1

.1...2.....3......5......8...13....21.34

.1...5....25....161...1112.8787.76156

.1..13...272...7776.287311

.1..42..4070.626649

.1.155.79221

.1.636

Examples

			Some solutions for n=4 k=4
..0..0..0..1..1..1..1....0..0..0..1..1..1..1....0..0..0..1..1..1..1
..0..1..1..0..0..1..1....0..1..1..0..0..1..1....0..0..0..1..1..1..1
..0..1..1..0..1..0..1....0..1..1..0..1..0..1....0..1..1..0..0..1..1
..1..0..0..1..0..1..1....1..0..0..1..1..1..0....1..0..0..1..1..0..1
..1..0..1..1..1..0..0....1..0..1..0..0..1..1....1..1..1..0..0..1..0
..1..1..0..1..0..1..0....1..1..0..1..1..0..0....1..1..1..0..1..0..0
..1..1..1..0..1..0..0....1..1..1..1..0..0..0....1..1..1..1..0..0..0
		

Crossrefs

Column 2 is A229161(n+1).

Column 3 is A229162(n+2).

Column 4 is A229163(n+3).

Column 5 is A229164(n+4).

Row 3 is A000045(n+1).

Row 4 is A181344(n+3).

Extensions

More terms from Sean A. Irvine, Sep 12 2019