A266902 Number of nX2 arrays containing 2 copies of 0..n-1 with no element 1 greater than its north, west or southwest neighbor modulo n and the upper left element equal to 0.

1, 0, 1, 13, 331, 17651, 1386377, 148410280, 20588092054, 3584553946578, 764734875953730, 196150243865801221

Offset

1,4

Comments

Column 2 of A266904.

Links

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

Example

Some solutions for n=6
..0..4....0..3....0..2....0..2....0..5....0..4....0..2....0..2....0..2....0..4
..4..1....4..1....0..5....3..2....0..3....5..1....3..1....4..1....2..1....4..1
..3..0....1..5....2..4....0..4....5..2....4..0....3..5....3..5....5..3....1..5
..3..5....5..2....5..3....5..3....3..1....1..3....0..4....1..3....5..3....3..3
..2..1....3..0....4..1....4..1....1..4....3..2....5..4....4..2....4..0....0..2
..2..5....2..4....1..3....1..5....4..2....2..5....2..1....0..5....1..4....5..2

Crossrefs

Cf. A266904.

Sequence in context: A348087 A142543 A258297 * A029807 A372182 A097308

Adjacent sequences: A266899 A266900 A266901 * A266903 A266904 A266905

Keyword

nonn

Author

R. H. Hardin, Jan 05 2016

Status

approved