A220329 Equals two maps: number of 2Xn binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal and antidiagonal neighbors in a random 0..1 2Xn array.

1, 4, 16, 48, 174, 658, 2482, 9229, 33982, 125217, 461351, 1699127, 6252129, 22995280, 84546207, 310785413, 1142206689, 4197260747, 15421867303, 56659522539, 208152496049, 764662949438, 2808941077111, 10318186228202

Offset: 1

Author

R. H. Hardin Dec 10 2012

Keywords

• nonn

Comments

Row 2 of A220328

Examples

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

Links

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