A210397 Number of (n+1) X 2 0..3 arrays with every 2 X 2 subblock having one or three distinct values, and new values 0..3 introduced in row major order.

7, 59, 549, 5167, 48689, 458859, 4324477, 40755719, 384099369, 3619917187, 34115652149, 321520538079, 3030147451297, 28557409213979, 269137272730989, 2536465091434807, 23904734913837209, 225288474590274099

Offset

1,1

Comments

Column 1 of A210404.

Links

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

Formula

Empirical: a(n) = 10*a(n-1) - 5*a(n-2) - 4*a(n-3).

Empirical g.f.: x*(1 - 2*x)*(7 + 3*x) / ((1 - x)*(1 - 9*x - 4*x^2)). - Colin Barker, Jul 15 2018

Example

Some solutions for n=4:
..0..0....0..0....0..0....0..0....0..1....0..1....0..0....0..0....0..1....0..0
..0..0....0..0....0..0....1..2....0..2....2..2....0..0....0..0....0..2....0..0
..0..0....0..0....0..0....0..1....0..1....1..0....0..0....0..0....3..3....1..2
..1..2....0..0....1..2....1..3....1..2....0..3....1..2....0..0....3..3....2..0
..1..0....1..2....2..0....3..0....2..3....0..1....3..3....0..0....1..2....2..3

Crossrefs

Cf. A210404.

Sequence in context: A322667 A363105 A101487 * A099659 A358599 A135150

Adjacent sequences: A210394 A210395 A210396 * A210398 A210399 A210400

Keyword

nonn

Author

R. H. Hardin, Mar 21 2012

Status

approved