A208173 Number of nX6 0..3 arrays with new values 0..3 introduced in row major order and no element equal to more than one of its immediate leftward or upward neighbors.

187, 506493, 1496307201, 4422202024212, 13069424064243420, 38625516979536823947, 114154269785454920027391, 337372761040287875038964700, 997075099388051313174129747636

Offset: 1

Author

R. H. Hardin Feb 24 2012

Keywords

• nonn

Comments

Column 6 of A208175

Examples

			Some solutions for n=4
..0..0..1..0..0..0....0..1..0..0..1..0....0..0..0..1..0..2....0..0..0..0..1..1
..0..1..2..1..1..3....1..0..2..3..1..3....2..0..1..3..2..0....2..0..2..2..1..0
..3..3..2..0..0..2....2..2..1..1..3..2....0..1..0..1..0..1....3..2..3..0..2..3
..1..1..3..1..0..0....0..1..0..3..0..1....3..3..3..2..3..0....3..0..1..2..3..2
		

Links

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