A199241 Number of nX3 0..2 arrays with values 0..2 introduced in row major order, the number of instances of each value within one of each other, and every element equal to zero or two horizontal or vertical neighbors.

1, 2, 6, 25, 110, 472, 2080, 9279, 41704, 187500, 853012, 3919309, 18163022, 84589504, 395762792, 1858908001, 8762833946, 41439737234, 196527899276, 934460643457, 4453641597888, 21271612632536, 101795771318046

Offset: 1

Author

R. H. Hardin Nov 04 2011

Keywords

• nonn

Comments

Column 3 of A199246

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..64