A188417 Number of (2*n)Xn binary arrays with rows in nonincreasing order, 2 ones in every column and no more than 3 ones in any row

1, 3, 16, 124, 1308, 17443, 282349, 5396178, 119324602, 3005520274, 85152637884, 2685936442822, 93514176139534

Offset

1,2

Comments

Row 2 of A188416

Links

Table of n, a(n) for n=1..13.

Example

All solutions for 4X2
..1..1....1..1....1..0
..1..0....1..1....1..0
..0..1....0..0....0..1
..0..0....0..0....0..1

Crossrefs

Sequence in context: A190291 A090135 A351423 * A327826 A157457 A365626

Adjacent sequences: A188414 A188415 A188416 * A188418 A188419 A188420

Keyword

nonn

Author

R. H. Hardin Mar 30 2011

Status

approved