A206143 Number of (n+1) X 2 0..2 arrays with every 2 X 3 or 3 X 2 subblock having exactly three counterclockwise and three clockwise edge increases.

81, 60, 162, 486, 1458, 4374, 13122, 39366, 118098, 354294, 1062882, 3188646, 9565938, 28697814, 86093442, 258280326, 774840978, 2324522934, 6973568802, 20920706406, 62762119218, 188286357654, 564859072962, 1694577218886

Offset

1,1

Comments

Column 1 of A206150.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) for n > 3.

Example

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

Crossrefs

Sequence in context: A033401 A143756 A206150 * A087410 A177842 A075691

Adjacent sequences: A206140 A206141 A206142 * A206144 A206145 A206146

Keyword

nonn

Author

R. H. Hardin, Feb 04 2012

Status

approved