A280852 Number of n X n 0..2 arrays with no element equal to more than one of its king-move neighbors and with new values introduced in order 0 sequentially upwards.

1, 9, 46, 124, 282, 712, 1738, 4124, 9562, 21752, 48730, 107992, 237082, 516376, 1117210

Offset: 1

Author

R. H. Hardin, Jan 09 2017

Keywords

• nonn

Comments

Diagonal of A280859.

Examples

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

Crossrefs

Cf. A280859.