A268157 Number of n X 3 arrays containing 3 copies of 0..n-1 with every element equal to at least one vertical or antidiagonal neighbor and the top left element equal to 0.

0, 1, 8, 36, 456, 6360, 93600, 1784160, 38102400, 899579520, 23960966400, 699741504000

Offset

1,3

Comments

Column 3 of A268159.

Links

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

Example

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

Crossrefs

Cf. A268159.

Sequence in context: A181072 A058823 A244301 * A203020 A276175 A050536

Adjacent sequences: A268154 A268155 A268156 * A268158 A268159 A268160

Keyword

nonn

Author

R. H. Hardin, Jan 27 2016

Status

approved