A232154 Number of n X n 0..3 arrays with every 0 next to a 1, every 1 next to a 2 and every 2 next to a 3 horizontally, vertically or antidiagonally, and no adjacent values equal.

1, 18, 290, 7770, 382996, 36275078, 6564512068, 2246994465516, 1482101422338982, 1881388287368571956

Offset: 1

Author

R. H. Hardin, Nov 19 2013

Keywords

• nonn

Comments

Diagonal of A232161

Examples

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