A220937 Equals two maps: number of 3Xn binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal and antidiagonal neighbors in a random 0..2 3Xn array.

1, 12, 92, 673, 5912, 48212, 395844, 3232729, 26184472, 211363254

Offset: 1

Author

R. H. Hardin Dec 25 2012

Keywords

• nonn

Comments

Row 3 of A220935

Examples

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