A188418 Number of (3*n)Xn binary arrays with rows in nonincreasing order, 3 ones in every column and no more than 3 ones in any row

1, 4, 39, 723, 21965, 968230, 57967660, 4505774905, 439923593145, 52601045792520

Offset

1,2

Comments

Row 3 of A188416

Links

Table of n, a(n) for n=1..10.

Example

All solutions for 6X2
..1..0....1..1....1..1....1..1
..1..0....1..1....1..0....1..1
..1..0....1..0....1..0....1..1
..0..1....0..1....0..1....0..0
..0..1....0..0....0..1....0..0
..0..1....0..0....0..0....0..0

Crossrefs

Sequence in context: A132612 A129463 A299426 * A136653 A165434 A348118

Adjacent sequences: A188415 A188416 A188417 * A188419 A188420 A188421

Keyword

nonn

Author

R. H. Hardin Mar 30 2011

Status

approved