A204605 Number of (n+2)X8 0..2 arrays with every 3X3 subblock having three strictly increasing elements in a row horizontally, vertically or nw-to-se diagonally exactly one way

153711850, 304865717, 327968423, 774393122, 1139760144, 1719348416, 9620299328, 81184579243, 606122835152, 4770658099472, 36670194434029, 269385186521216, 2109808033784128, 16211635789930370, 119093074670884992

Offset

1,1

Comments

Column 6 of A204607

Links

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

Formula

Empirical: a(n) = 442*a(n-3) +43*a(n-6) for n>17

Example

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

Crossrefs

Sequence in context: A221555 A212941 A022249 * A289248 A251489 A205641

Adjacent sequences: A204602 A204603 A204604 * A204606 A204607 A204608

Keyword

nonn

Author

R. H. Hardin Jan 17 2012

Status

approved