A206980 Number of n X n 0..1 arrays avoiding the patterns 0 1 0 or 1 0 1 in any row, column, diagonal or antidiagonal.

2, 16, 58, 556, 7500, 119224, 2926752, 111202694, 5582239354, 398193149976, 43178426815216, 6623459579619334, 1414003622686654366, 443957184641073369216

Offset: 1

Author

R. H. Hardin Feb 14 2012

Keywords

• nonn

Comments

Diagonal of A206987

Examples

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