A264702 Number of nX2 arrays of permutations of 0..n*2-1 with rows nondecreasing modulo 2 and columns nondecreasing modulo 6.

1, 3, 6, 36, 288, 2240, 20736, 264384, 2892672, 63452160, 1528823808, 36691771392, 941182156800, 29143203840000, 803229696000000, 36978425856000000

Offset

1,2

Comments

Column 2 of A264704.

Links

Table of n, a(n) for n=1..16.

Example

Some solutions for n=7
..6..0....0..1....6..7....0..7...12..7...12..7....6..0...12..1....6..0....6.12
.12..7...12..2...12..1...12.13....0..1....0..1...12.13....6.13...12.13....0..7
.13..9....6..8....0.13....6..2....6.13....6..9....3..1....0..7....1..9...13..1
..1..3....7..9....2..8....1..3....8..9...13..3....9..7....2..9....7..3....8..3
..2..4...13..3....4..3....8..9....2..3....2..4....4..2....8.10....8..4....2..4
..8.10....4.11...10..9....4.10...10..4....8.10...10..8....3..5....2..5....9..5
..5.11...10..5....5.11...11..5....5.11....5.11...11..5....4.11...10.11...10.11

Crossrefs

Cf. A264704.

Sequence in context: A372003 A120595 A048642 * A077532 A174666 A211893

Adjacent sequences: A264699 A264700 A264701 * A264703 A264704 A264705

Keyword

nonn

Author

R. H. Hardin, Nov 21 2015

Status

approved