A265867 Number of nX2 arrays containing 2 copies of 0..n-1 with no element plus any antidiagonal neighbor equal to n-1.

1, 2, 42, 984, 48216, 2869200, 278125200, 31015797120, 4991834736000, 896085889171200, 215916261060729600, 56895400548095155200

Offset: 1

Author

R. H. Hardin, Dec 17 2015

Keywords

• nonn

Comments

Column 2 of A265870.

Examples

			Some solutions for n=4
..0..3....0..2....3..0....1..0....3..0....2..1....0..3....3..3....1..2....1..1
..2..0....0..1....0..2....2..0....2..0....3..3....3..1....2..1....2..0....3..3
..1..2....3..1....2..3....2..1....2..1....1..0....1..2....1..2....0..1....2..0
..3..1....3..2....1..1....3..3....1..3....2..0....2..0....0..0....3..3....0..2
		

Crossrefs

Cf. A265870.