A206144 Number of (n+1) X 3 0..2 arrays with every 2 X 3 or 3 X 2 subblock having exactly three counterclockwise and three clockwise edge increases.

60, 246, 1122, 5118, 23346, 106494, 485778, 2215902, 10107954, 46107966, 210323922, 959403678, 4376370546, 19963045374, 91062485778, 415386338142, 1894806719154, 8643260919486, 39426691159122, 179846933956638

Offset

1,1

Comments

Column 2 of A206150.

Links

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

Formula

Empirical: a(n) = 5*a(n-1) - 2*a(n-2) for n > 3.

Empirical g.f.: 6*x*(2 - x)*(5 - 2*x) / (1 - 5*x + 2*x^2). - Colin Barker, Mar 04 2018

Example

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

Crossrefs

Cf. A206150.

Sequence in context: A263225 A019285 A261970 * A008428 A206232 A075295

Adjacent sequences: A206141 A206142 A206143 * A206145 A206146 A206147

Keyword

nonn

Author

R. H. Hardin, Feb 04 2012

Status

approved