A210005 Number of (n+1) X 2 0..2 arrays containing all values 0..2 with every 2 X 2 subblock having two or three distinct values, and new values 0..2 introduced in row major order.

6, 88, 893, 8217, 73035, 640495, 5586791, 48624987, 422832951, 3675525835, 31945165919, 277628591571, 2412749978775, 20967950350123, 182220740086511, 1583575892972451, 13761939669663303, 119597001511594267

Offset

1,1

Comments

Column 1 of A210012.

Links

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

Formula

Empirical: a(n) = 11*a(n-1) - 16*a(n-2) - 34*a(n-3) - 12*a(n-4).

Empirical g.f.: x*(3 + 2*x)*(2 + 6*x + 3*x^2) / ((1 - 3*x - 2*x^2)*(1 - 8*x - 6*x^2)). - Colin Barker, Jul 14 2018

Example

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

Crossrefs

Cf. A210012.

Sequence in context: A173224 A210012 A226426 * A178296 A122770 A265267

Adjacent sequences: A210002 A210003 A210004 * A210006 A210007 A210008

Keyword

nonn

Author

R. H. Hardin, Mar 16 2012

Status

approved