A202556 Number of nX4 0,1 arrays with the row and column sums nondecreasing.

5, 37, 235, 1526, 9325, 57255, 342295, 2048759, 12097875, 71623580, 421070137, 2483305077, 14588495861, 85996521989, 505767515227, 2984447588198, 17583885515973, 103920730449567, 613473612747653, 3631554358770128

Offset: 1

Author

R. H. Hardin Dec 21 2011

Keywords

• nonn

Comments

Column 4 of A202560

Examples

			Some solutions for n=6
..1..0..1..0....0..0..0..0....0..0..1..0....0..0..0..0....0..1..0..0
..0..1..0..1....0..0..0..0....1..0..0..1....0..1..0..1....1..0..0..0
..0..1..0..1....0..0..0..0....0..1..0..1....1..0..0..1....0..0..0..1
..0..0..1..1....1..0..0..1....0..1..0..1....0..1..1..0....0..0..0..1
..1..1..0..0....0..0..1..1....1..0..1..1....0..0..1..1....0..0..1..0
..0..0..1..1....0..1..1..1....0..1..1..1....1..1..1..1....0..0..0..1
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..46