A183587 1/24 the number of (n+1) X 3 0..3 arrays with every 2 X 2 subblock containing exactly three distinct values.

56, 1243, 27380, 603766, 13311808, 293504588, 6471298096, 142681644568, 3145899035840, 69361976167600, 1529319179389504, 33719009781468512, 743449527042830848, 16391857377908771008, 361413893645653683968

Offset

1,1

Comments

Column 2 of A183594.

Links

R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n) = 24*a(n-1) - 30*a(n-2) - 296*a(n-3) + 192*a(n-4).

Empirical g.f.: x*(56 - 101*x - 772*x^2 + 512*x^3) / (1 - 24*x + 30*x^2 + 296*x^3 - 192*x^4). - Colin Barker, Mar 29 2018

Example

Some solutions with a(1,1)=0 for 5 X 3:
..0..0..0....0..0..0....0..0..0....0..0..0....0..0..0....0..0..0....0..0..0
..1..3..2....3..2..3....2..3..1....1..2..3....1..3..2....1..3..1....2..1..2
..0..1..3....2..1..1....3..0..3....1..3..1....0..1..2....1..0..1....3..2..3
..0..3..0....1..0..2....0..1..0....3..0..1....2..0..1....2..0..2....0..3..1
..1..0..2....0..3..0....2..1..3....3..2..2....3..0..3....3..3..2....2..2..2

Crossrefs

Cf. A183594.

Sequence in context: A140901 A160346 A219371 * A219469 A278079 A025597

Adjacent sequences: A183584 A183585 A183586 * A183588 A183589 A183590

Keyword

nonn

Author

R. H. Hardin, Jan 05 2011

Status

approved