A266040 Number of nX2 arrays containing 2 copies of 0..n-1 with no element plus any vertical or antidiagonal neighbor equal to n-1.

1, 0, 8, 104, 6440, 312960, 36965712, 3615441408, 668391093888, 108118788084480, 29018593889026560, 7014015968947706880

Offset

1,3

Comments

Column 2 of A266042.

Links

Table of n, a(n) for n=1..12.

Example

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

Crossrefs

Cf. A266042.

Sequence in context: A034300 A266044 A359801 * A354173 A146346 A285745

Adjacent sequences: A266037 A266038 A266039 * A266041 A266042 A266043

Keyword

nonn

Author

R. H. Hardin, Dec 20 2015

Status

approved