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

1,2

Comments

Diagonal of A265458.

Links

Table of n, a(n) for n=1..8.

Example

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.

Sequence in context: A232595 A335685 A159405 * A213402 A248804 A060617

Adjacent sequences: A265447 A265448 A265449 * A265451 A265452 A265453

Keyword

nonn

Author

R. H. Hardin, Dec 09 2015

Status

approved