A183703 Number of (n+1) X 3 0..3 arrays with every 2 X 2 subblock nonsingular.

2472, 108624, 4760784, 208772880, 9154058448, 401390133264, 17600152230096, 771732813754128, 33838983410458320, 1483773801471835152, 65060601957611490000, 2852781167483605911312, 125088919099890142198992

Offset

1,1

Comments

Column 2 of A183710.

Links

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

Formula

Empirical: a(n) = 29*a(n-1) + 617*a(n-2) + 1587*a(n-3) - 4104*a(n-4).

Empirical g.f.: 24*x*(103 + 1539*x + 3561*x^2 - 9747*x^3) / (1 - 29*x - 617*x^2 - 1587*x^3 + 4104*x^4). - Colin Barker, Apr 04 2018

Example

Some solutions for 5 X 3:
..2..0..2....2..0..2....2..0..2....2..0..2....2..0..2....2..0..2....2..0..2
..0..2..0....0..2..0....0..2..0....0..2..2....0..2..0....0..2..0....0..2..0
..1..3..3....1..3..3....1..1..1....1..0..2....1..0..2....1..2..3....1..0..1
..1..2..1....2..3..0....0..3..2....2..1..3....2..2..1....2..2..1....0..2..3
..2..0..3....3..1..2....1..2..0....3..1..2....0..3..3....1..2..0....2..2..0

Crossrefs

Cf. A183710.

Sequence in context: A204614 A204798 A224723 * A282559 A278733 A236785

Adjacent sequences: A183700 A183701 A183702 * A183704 A183705 A183706

Keyword

nonn

Author

R. H. Hardin, Jan 06 2011

Status

approved