A266852 Number of nX2 arrays containing 2 copies of 0..n-1 with no element 1 greater than its north, west, northeast or southeast neighbor modulo n and the upper left element equal to 0.

1, 0, 1, 6, 171, 7637, 597012, 61297802, 8302773834, 1419843626102, 298978224319607

Offset

1,4

Comments

Column 2 of A266854.

Links

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

Example

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

Crossrefs

Cf. A266854.

Sequence in context: A198176 A264358 A264796 * A266311 A323820 A317795

Adjacent sequences: A266849 A266850 A266851 * A266853 A266854 A266855

Keyword

nonn

Author

R. H. Hardin, Jan 04 2016

Status

approved