A200800 Number of nX7 0..3 arrays with values 0..3 introduced in row major order and each element equal to no more than two horizontal and vertical neighbors.

715, 9676364, 122478253815, 1557479347400065, 19804473216531794553, 251826890612151285556718, 3202145671418507455058837791

Offset: 1

Author

R. H. Hardin Nov 22 2011

Keywords

• nonn

Comments

Column 7 of A200801

Examples

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