A266865 Number of nX2 arrays containing 2 copies of 0..n-1 with no element 1 greater than its west or northeast neighbor modulo n and the upper left element equal to 0.

1, 0, 4, 72, 2760, 154240, 12199500, 1293877704, 177333949072, 30510421277760, 6439108605861780, 1635806769641077000

Offset

1,3

Comments

Column 2 of A266867.

Links

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

Example

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

Crossrefs

Cf. A266867.

Sequence in context: A384086 A295383 A309980 * A327882 A003718 A012947

Adjacent sequences: A266862 A266863 A266864 * A266866 A266867 A266868

Keyword

nonn

Author

R. H. Hardin, Jan 04 2016

Status

approved