A186468 Number of (n+1)X6 0..2 arrays with every 2X2 subblock commuting with each of its horizontal and vertical 2X2 subblock neighbors

966, 903, 3190, 4875, 13278, 16083, 40626, 52755, 129102, 182841, 418022, 632281, 1362100, 2157562, 4454506, 7311254, 14630604, 24660486, 48209460, 82892994, 159253412, 277942714, 527083732, 930249586, 1747039708, 3109258106

Offset

1,1

Comments

Column 5 of A186472

Links

R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n)=2*a(n-1)+a(n-2)-4*a(n-3)+4*a(n-4)-2*a(n-5) for n>14

Example

Some solutions for 3X6
..2..1..0..1..0..2....1..1..0..0..0..1....1..0..0..0..1..0....0..0..0..0..0..2
..1..0..1..0..1..0....2..0..1..0..0..0....2..0..0..0..0..1....1..0..0..0..0..0
..0..1..0..1..0..1....0..2..0..1..0..0....0..2..0..0..0..0....2..1..0..0..0..0

Crossrefs

Sequence in context: A093232 A252259 A225684 * A345549 A345802 A014363

Adjacent sequences: A186465 A186466 A186467 * A186469 A186470 A186471

Keyword

nonn

Author

R. H. Hardin Feb 22 2011

Status

approved