A208097 Number of 2 X n nonnegative integer arrays with new values 0 upwards introduced in row major order and no element equal to any horizontal, diagonal or antidiagonal neighbor (colorings ignoring permutations of colors).

2, 4, 30, 377, 7239, 193228, 6752442, 296290708, 15835464207, 1007305486325, 74890158775564, 6413015600048526, 624933541074620780, 68603269124243415049, 8411144435499643711885, 1143251056778815843116186

Offset: 1

Author

R. H. Hardin, Feb 23 2012

Keywords

• nonn

Comments

Row 2 of A208096.

Examples

			Some solutions for n=4:
..0..1..2..1....0..1..0..1....0..1..2..0....0..1..2..0....0..1..2..0
..3..1..4..5....0..1..0..2....0..1..3..1....0..1..2..0....3..1..2..4
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..19