A204604 Number of (n+2)X7 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

16247580, 40672735, 43980907, 69792825, 207096000, 1139760144, 6656676736, 61015724528, 513802492708, 3004591151584, 27074363705888, 227330083011172, 1328325507137504, 11969420064914272, 100501902404767796

Offset

1,1

Comments

Column 5 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>16

Example

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

Crossrefs

Sequence in context: A179585 A105650 A234457 * A253716 A216004 A155949

Adjacent sequences: A204601 A204602 A204603 * A204605 A204606 A204607

Keyword

nonn

Author

R. H. Hardin Jan 17 2012

Status

approved