A265450 Number of n X n 0..2n-2 arrays with each element differing from its horizontal and vertical neighbors by one or two.

1, 18, 7422, 13943772, 122895678174, 5327856426356284, 1191337567990711362900, 1410907091881274891065515756

Offset: 1

Author

R. H. Hardin, Dec 09 2015

Keywords

• nonn

Comments

Diagonal of A265458.

Examples

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

Crossrefs

Cf. A265458.