A203180 Number of nX7 0..2 arrays with every 1 immediately preceded by 0 to the left or above, no 0 immediately preceded by a 0, and every 2 immediately preceded by 0 1 to the left or above.

5, 18, 235, 2466, 23083, 223567, 2208945, 22411843, 216858412, 2141041521, 21294389765, 209517628754, 2070288232686, 20420464639642, 201913230471755, 1993188902599209, 19665745111235770, 194376407794905718

Offset: 1

Author

R. H. Hardin Dec 30 2011

Keywords

• nonn

Comments

Column 7 of A203181

Examples

			Some solutions for n=5
..0..1..2..0..1..0..1....0..1..0..1..2..0..1....0..1..0..1..2..0..1
..1..0..1..2..0..1..0....1..0..1..2..0..1..0....1..0..1..0..1..2..0
..0..1..0..1..1..2..1....0..1..0..1..1..0..1....0..1..0..1..2..0..1
..1..0..1..0..1..0..1....1..0..1..0..2..1..2....1..2..1..2..0..1..0
..0..1..2..1..0..1..0....2..1..0..1..2..0..1....0..1..0..1..1..0..1
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..210