A206628 Number of (n+1) X 2 0..2 arrays with every 2 X 3 or 3 X 2 subblock having no more than four equal edges, and new values 0..2 introduced in row major order.

14, 121, 1085, 9729, 87238, 782246, 7014246, 62895364, 563970356, 5057011236, 45345224920, 406601711384, 3645917557848, 32692225503376, 293144754758096, 2628571347438864, 23569882170595936, 211346496672826976

Offset

1,1

Comments

Column 1 of A206635.

Links

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

Formula

Empirical: a(n) = 8*a(n-1) + 8*a(n-2) + 6*a(n-3) for n>4.

Empirical g.f.: x*(14 + 9*x + 5*x^2 - 3*x^3) / (1 - 8*x - 8*x^2 - 6*x^3). - Colin Barker, Mar 04 2018

Example

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

Crossrefs

Cf. A206635.

Sequence in context: A249980 A206635 A163942 * A370966 A235710 A239544

Adjacent sequences: A206625 A206626 A206627 * A206629 A206630 A206631

Keyword

nonn

Author

R. H. Hardin, Feb 10 2012

Status

approved