A208467 Number of 2Xn nonnegative integer arrays with new values 0 upwards introduced in row major order and no element equal to more than two of its immediate leftward or upward or right-upward antidiagonal neighbors.

2, 15, 198, 4041, 113458, 4132120, 187612143, 10318694804, 672619407731, 51074630353994, 4455159144290726, 441285917587055633, 49152543937083199076, 6105599904286957450405, 839738743273230043872218

Offset: 1

Author

R. H. Hardin Feb 27 2012

Keywords

• nonn

Comments

Row 2 of A208466

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..34