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

1,3

Comments

Diagonal of A216460

Links

Table of n, a(n) for n=1..7.

Example

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

Crossrefs

Sequence in context: A292332 A177813 A292338 * A243144 A234619 A308614

Adjacent sequences: A216453 A216454 A216455 * A216457 A216458 A216459

Keyword

nonn

Author

R. H. Hardin Sep 07 2012

Status

approved