A199640 Number of n X n 0..2 arrays with values 0..2 introduced in row major order and each element equal to one or two horizontal and vertical neighbors.

0, 3, 112, 29229, 32177372, 176701683386, 4539946639286136

Offset: 1

Author

R. H. Hardin Nov 08 2011

Keywords

• nonn

Comments

Diagonal of A199647

Examples

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