A209790 Half the number of (n+1) X 3 0..2 arrays with every 2 X 2 subblock having exactly one duplicate clockwise edge difference.

204, 3171, 49056, 759642, 11761044, 182095128, 2819342124, 43651363500, 675845981124, 10463998747116, 162012162212700, 2508404424354996, 38837163012482148, 601308631223158716, 9309950622871199676

Offset

1,1

Comments

Column 2 of A209796.

Links

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

Formula

Empirical: a(n) = 14*a(n-1) + 27*a(n-2) - 64*a(n-3) + 22*a(n-4).

Empirical g.f.: 3*x*(68 + 105*x - 282*x^2 + 99*x^3) / (1 - 14*x - 27*x^2 + 64*x^3 - 22*x^4). - Colin Barker, Jul 13 2018

Example

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

Crossrefs

Cf. A209796.

Sequence in context: A234789 A099105 A253680 * A348603 A194192 A339199

Adjacent sequences: A209787 A209788 A209789 * A209791 A209792 A209793

Keyword

nonn

Author

R. H. Hardin, Mar 13 2012

Status

approved