A266884 Number of nX2 arrays containing 2 copies of 0..n-1 with no element 1 greater than its north, northeast or northwest neighbor modulo n and the upper left element equal to 0.

1, 0, 1, 22, 525, 26100, 1916217, 197069522, 26421089461, 4477779976928, 934604232708721

Offset

1,4

Comments

Column 2 of A266886.

Links

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

Example

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

Crossrefs

Cf. A266886.

Sequence in context: A121904 A158629 A253777 * A182610 A320766 A203456

Adjacent sequences: A266881 A266882 A266883 * A266885 A266886 A266887

Keyword

nonn

Author

R. H. Hardin, Jan 05 2016

Status

approved