A216456 Number of horizontal, diagonal and antidiagonal neighbor colorings of the even squares of an n X n array with new integer colors introduced in row major order.

1, 1, 7, 203, 580479, 6423127757, 22530453266592757

Offset: 1

Author

R. H. Hardin Sep 07 2012

Keywords

• nonn

Comments

Diagonal of A216460

Examples

			Some solutions for n=4
..0..x..1..x....0..x..1..x....0..x..1..x....0..x..1..x....0..x..1..x
..x..2..x..3....x..2..x..3....x..2..x..3....x..2..x..3....x..2..x..3
..3..x..1..x....3..x..4..x....4..x..0..x....3..x..4..x....0..x..1..x
..x..4..x..2....x..5..x..2....x..1..x..3....x..1..x..2....x..4..x..0