A275497 Number of n X n 0..2 arrays with no element equal to any value at offset (-2,-1), (-2,0) or (-1,-1) and new values introduced in order 0..2.

1, 9, 80, 656, 4180, 68080, 1643372, 58423188, 3045734096, 235680645520, 26923774835716, 4558306996574952

Offset: 1

Author

R. H. Hardin, Jul 30 2016

Keywords

• nonn

Comments

Diagonal of A275504.

Examples

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

Crossrefs

Cf. A275504.