A186566 Number of (n+2)X9 0..2 arrays with every 3X3 subblock commuting with each horizontal and vertical neighbor 3X3 subblock

29303, 4033, 6511, 14845, 27391, 36133, 47719, 60973, 82447, 122725, 185863, 278125, 425791, 645685, 993687, 1533053, 2343151, 3593989, 5522887, 8433037, 12920671, 19843157, 30348343, 46510173, 71399503, 109274533, 167438119

Offset

1,1

Comments

Column 7 of A186568

Links

R. H. Hardin, Table of n, a(n) for n = 1..181

Formula

Empirical: a(n)=2*a(n-1)-a(n-2)+2*a(n-3)-4*a(n-4)+2*a(n-5)+2*a(n-6)-2*a(n-7) for n>15

Example

Some solutions for 4X9
..0..0..0..0..0..0..0..0..0....2..0..0..0..0..0..0..1..2
..1..0..0..0..0..0..0..0..1....0..2..0..0..0..0..0..0..0
..1..1..0..0..0..0..0..0..0....0..0..2..0..0..0..0..0..0
..2..1..1..0..0..0..0..0..0....0..0..0..2..0..0..0..0..0

Crossrefs

Sequence in context: A194619 A058652 A250940 * A083740 A083739 A329538

Adjacent sequences: A186563 A186564 A186565 * A186567 A186568 A186569

Keyword

nonn

Author

R. H. Hardin Feb 23 2011

Status

approved