A210006 Number of (n+1) X 3 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.

88, 2691, 70923, 1808865, 45763485, 1155440875, 29157605895, 735696878225, 18562285346341, 468338954286595, 11816481504639071, 298136973245043705, 7522175051206144237, 189788991513097693371, 4788490127902930108215

Offset

1,1

Comments

Column 2 of A210012.

Links

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

Formula

Empirical: a(n) = 30*a(n-1) - 109*a(n-2) - 290*a(n-3) + 96*a(n-4) + 136*a(n-5) - 48*a(n-6).

Empirical g.f.: x*(88 + 51*x - 215*x^2 + 14*x^3 + 84*x^4 - 24*x^5) / ((1 - 6*x - 3*x^2 + 2*x^3)*(1 - 24*x - 32*x^2 + 24*x^3)). - Colin Barker, Jul 14 2018

Example

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

Crossrefs

Cf. A210012.

Sequence in context: A245954 A248047 A107422 * A194491 A093288 A017804

Adjacent sequences: A210003 A210004 A210005 * A210007 A210008 A210009

Keyword

nonn

Author

R. H. Hardin, Mar 16 2012

Status

approved