A264558 Number of nX2 arrays of permutations of 0..n*2-1 with rows nondecreasing modulo 2 and columns nondecreasing modulo 3.

1, 3, 15, 156, 2032, 30912, 737280, 19491840, 585019584, 26539425792, 1275815411712, 65050879721472

Offset: 1

Author

R. H. Hardin, Nov 17 2015

Keywords

• nonn

Comments

Column 2 of A264560.

Examples

			Some solutions for n=4
..0..7....6..1....6..3....6..3....0..6....0..6....6..4....6..3....0..3....6..3
..6..4....3..7....0..7....0..1....4..3....7..3....3..7....0..1....6..1....0..4
..3..1....0..5....4..1....2..4....5..1....2..4....0..2....4..7....7..5....1..7
..2..5....4..2....2..5....5..7....2..7....5..1....1..5....2..5....4..2....2..5
		

Crossrefs

Cf. A264560.