A265660 Number of nX2 arrays containing 2 copies of 0..n-1 with no element plus any horizontal or vertical neighbor equal to n-1.

0, 0, 0, 112, 4912, 265440, 31924032, 3170361984, 597787563264, 97379218955520, 26489701471180800, 6432079809975552000

Offset

1,4

Comments

Column 2 of A265663.

Links

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

Example

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

Crossrefs

Cf. A265663.

Sequence in context: A172129 A304552 A103860 * A271032 A213803 A291214

Adjacent sequences: A265657 A265658 A265659 * A265661 A265662 A265663

Keyword

nonn

Author

R. H. Hardin, Dec 12 2015

Status

approved