A206614 Number of (n+1) X 2 0..2 arrays with every 2 X 3 or 3 X 2 subblock having no more than two equal edges, and new values 0..2 introduced in row major order.

14, 86, 580, 4035, 27895, 192358, 1327931, 9168477, 63292982, 436934969, 3016371943, 20823400074, 143753294443, 992394181981, 6850947582710, 47295197965905, 326500200032495, 2253978967732298, 15560239102262371

Offset

1,1

Comments

Column 1 of A206621.

Links

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

Formula

Empirical: a(n) = 7*a(n-1) - 5*a(n-2) + 36*a(n-3) - 42*a(n-4) for n>5.

Empirical g.f.: x*(14 - 12*x + 48*x^2 - 99*x^3 + 42*x^4) / (1 - 7*x + 5*x^2 - 36*x^3 + 42*x^4). - Colin Barker, Jun 17 2018

Example

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

Crossrefs

Cf. A206621.

Sequence in context: A213121 A125324 A126482 * A345107 A321941 A116343

Adjacent sequences: A206611 A206612 A206613 * A206615 A206616 A206617

Keyword

nonn

Author

R. H. Hardin, Feb 10 2012

Status

approved