A221134 Number of nX3 arrays of occupancy after each element moves to some horizontal or vertical neighbor, with no occupancy greater than 2.

2, 49, 656, 12544, 200072, 3485689, 58132316, 990486784, 16699002692, 282999528529, 4783766470826, 80965479678724, 1369496232351362, 23171487659654569, 391996208325992186, 6631958618350959364

Offset: 1

Author

R. H. Hardin Jan 02 2013

Keywords

• nonn

Comments

Column 3 of A221139

Examples

			Some solutions for n=3
..2..1..1....1..2..0....0..2..2....2..1..0....0..2..2....0..1..2....0..2..2
..1..0..1....1..2..0....1..1..1....2..1..2....0..2..1....2..0..1....1..0..1
..0..2..1....1..2..0....0..1..1....0..0..1....0..2..0....2..1..0....2..1..0
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..29

Formula

Empirical: a(n) = 21*a(n-1) -1450*a(n-3) +4782*a(n-4) -372*a(n-5) +1450*a(n-6) +69*a(n-8) +a(n-9)