A204600 Number of (n+2)X3 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

3562, 29678, 328845, 2275645, 16247580, 153711850, 1240455298, 9111381604, 76764201360, 642774112145, 4970541781364, 39956500934443, 331362692034969, 2645811447632755, 21088097910525745, 172146633446959131

Offset

1,1

Comments

Column 1 of A204607

Links

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

Formula

Empirical: a(n) = 307*a(n-3) +1269*a(n-4) +3014*a(n-5) +3034*a(n-6) +25372*a(n-7) +79370*a(n-8) +86184*a(n-9) -18348*a(n-10) +325463*a(n-11) +986531*a(n-12) -990300*a(n-13) -1055430*a(n-14) +897607*a(n-15) -320293*a(n-16) -227770*a(n-17) +280127*a(n-18) +510823*a(n-19) +29680*a(n-20) -200892*a(n-21) -53919*a(n-22) +324*a(n-23) +5832*a(n-24)

Example

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

Crossrefs

Sequence in context: A104207 A107646 A204607 * A204599 A206090 A357590

Adjacent sequences: A204597 A204598 A204599 * A204601 A204602 A204603

Keyword

nonn

Author

R. H. Hardin Jan 17 2012

Status

approved