A183812 1/81 the number of (n+1)X(n+1) 0..2 arrays with no 2X2 subblock being a reflection across the shared element pair of any horizontal or vertical neighbor.

1, 162, 163208, 1042063656, 41531687999736, 10425296660739253420

Offset: 1

Author

R. H. Hardin Jan 07 2011

Keywords

• nonn

Comments

Diagonal of A183819

Examples

			Some solutions with upper left block zero for 3X3
..0..0..2....0..0..0....0..0..2....0..0..0....0..0..2....0..0..0....0..0..0
..0..0..0....0..0..1....0..0..1....0..0..2....0..0..2....0..0..1....0..0..1
..2..2..0....0..1..2....1..1..1....1..1..1....1..2..1....2..0..1....1..2..1