A266306 Number of nX2 arrays containing 2 copies of 0..n-1 with no element 1 greater than its west neighbor modulo n and the upper left element equal to 0.

1, 1, 7, 171, 6666, 384360, 30900150, 3314400390, 457970055480, 79281706512960, 16813296291166200, 4287982048554619800

Offset

1,3

Comments

Column 2 of A266309.

Links

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

Example

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

Crossrefs

Cf. A266309.

Sequence in context: A157203 A178019 A337676 * A332117 A226598 A075599

Adjacent sequences: A266303 A266304 A266305 * A266307 A266308 A266309

Keyword

nonn

Author

R. H. Hardin, Dec 26 2015

Status

approved