A183332 Number of n X 4 binary arrays with each 1 adjacent to exactly two 0's.

3, 23, 66, 247, 899, 3254, 11883, 43207, 157266, 572571, 2084227, 7587166, 27619131, 100540587, 365994058, 1332312171, 4849957923, 17655092138, 64269069107, 233955917683, 851659617442, 3100259701471, 11285741436475, 41082996924906

Offset

1,1

Comments

Column 4 of A183335.

Links

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

Formula

Empirical: a(n)=2*a(n-1)+2*a(n-2)+9*a(n-3)+14*a(n-4)+20*a(n-5)+9*a(n-6)-4*a(n-7)-24*a(n-8)-46*a(n-9)-43*a(n-10)-35*a(n-11)-16*a(n-12)+6*a(n-13)+11*a(n-14)+8*a(n-15)+7*a(n-16)+2*a(n-17)+a(n-18)+2*a(n-19).

Example

Some solutions for 8 X 4
..0..1..1..0....0..0..0..1....0..1..0..1....1..0..1..0....0..0..0..1
..1..0..0..0....0..0..0..0....0..1..0..0....0..1..1..0....0..0..0..0
..1..0..0..0....0..0..1..1....0..1..1..0....1..1..0..0....1..1..0..0
..0..0..0..1....1..0..1..0....0..0..1..0....0..0..0..0....0..1..1..1
..0..0..0..1....1..0..1..1....0..0..1..0....0..0..1..1....0..0..0..0
..0..0..0..0....0..0..0..0....1..0..1..1....1..1..1..0....1..1..1..1
..1..1..0..0....1..1..1..1....1..0..0..0....0..0..0..0....0..0..0..0
..0..1..0..0....0..0..0..0....0..0..0..0....0..1..1..0....1..0..0..1

Crossrefs

Sequence in context: A299511 A299311 A300112 * A358422 A196325 A003531

Adjacent sequences: A183329 A183330 A183331 * A183333 A183334 A183335

Keyword

nonn

Author

R. H. Hardin Jan 03 2011

Status

approved