A266859 Number of nX2 arrays containing 2 copies of 0..n-1 with no element 1 greater than its north or southwest neighbor modulo n and the upper left element equal to 0.

1, 0, 4, 39, 1281, 67240, 5126572, 531096757, 71602080252, 12170470180300, 2544668908965896, 641689032354740060

Offset

1,3

Comments

Column 2 of A266861.

Links

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

Example

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

Crossrefs

Cf. A266861.

Sequence in context: A086217 A203197 A094156 * A049475 A264084 A080271

Adjacent sequences: A266856 A266857 A266858 * A266860 A266861 A266862

Keyword

nonn

Author

R. H. Hardin, Jan 04 2016

Status

approved