A266876 Number of nX2 arrays containing 2 copies of 0..n-1 with no element 1 greater than its north, southwest or northwest neighbor modulo n and the upper left element equal to 0.

1, 0, 1, 7, 351, 19773, 1567330, 166758092, 22928383502, 3956915450846, 837459080604863

Offset

1,4

Comments

Column 2 of A266878.

Links

Table of n, a(n) for n=1..11.

Example

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

Crossrefs

Cf. A266878.

Sequence in context: A234622 A142669 A239717 * A185062 A067556 A082098

Adjacent sequences: A266873 A266874 A266875 * A266877 A266878 A266879

Keyword

nonn

Author

R. H. Hardin, Jan 05 2016

Status

approved