A267221 Number of nX2 arrays containing 2 copies of 0..n-1 with no element 1 greater than its west, northeast or southeast neighbor modulo n and the upper left element equal to 0.

1, 0, 3, 35, 889, 52759, 4249084, 454920734, 62723579604, 10837409167674, 2294655530073038

Offset

1,3

Comments

Column 2 of A267222.

Links

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

Example

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

Crossrefs

Cf. A267222.

Sequence in context: A129505 A185752 A210897 * A135516 A231644 A368389

Adjacent sequences: A267218 A267219 A267220 * A267222 A267223 A267224

Keyword

nonn

Author

R. H. Hardin, Jan 12 2016

Status

approved