A188419 Number of (4*n) X n binary arrays with rows in nonincreasing order, four 1's in every column and no more than three 1's in any row.

1, 5, 81, 3217, 252493, 33313408, 6720357785, 1943505834628, 768799728447441

Offset: 1

Author

R. H. Hardin, Mar 30 2011

Keywords

• nonn

Comments

Row 4 of A188416.

Examples

			All solutions for 8 X 2
..1..0....1..1....1..1....1..1....1..1
..1..0....1..1....1..1....1..0....1..1
..1..0....1..1....1..1....1..0....1..0
..1..0....1..1....1..0....1..0....1..0
..0..1....0..0....0..1....0..1....0..1
..0..1....0..0....0..0....0..1....0..1
..0..1....0..0....0..0....0..1....0..0
..0..1....0..0....0..0....0..0....0..0
		

Crossrefs

Cf. A188416.