A222899 Number of n X n 0..3 arrays with no more than floor(n X n/2) elements unequal to at least one horizontal or antidiagonal neighbor, with new values introduced in row major 0..3 order.

1, 4, 45, 7794, 2117424, 10615237672, 51666240687220, 4291633334520814783, 347033965049827951084160

Offset: 1

Author

R. H. Hardin, Mar 09 2013

Keywords

• nonn

Comments

Diagonal of A222906.

Examples

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

Crossrefs

Cf. A222906.