A238317 Number of (n+1)X(2+1) 0..2 arrays with no element greater than all horizontal neighbors or less than all vertical neighbors

9, 67, 376, 1867, 9489, 50232, 267174, 1408341, 7395987, 38886701, 204722786, 1077853232, 5673085286, 29856142160, 157133586571, 827031030519, 4352855509300, 22909846720541, 120578232671314, 634623931681625

Offset

1,1

Comments

Column 2 of A238323

Links

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

Formula

Empirical: a(n) = 6*a(n-1) -12*a(n-2) +39*a(n-3) +6*a(n-4) +62*a(n-5) +49*a(n-6) +33*a(n-7) -32*a(n-8) -41*a(n-9) -12*a(n-10) +6*a(n-11) +5*a(n-12) +a(n-13)

Example

Some solutions for n=5
..2..2..1....1..1..1....0..1..1....1..1..1....2..2..2....1..2..2....0..2..2
..1..1..1....1..1..1....0..0..0....0..0..0....0..0..0....0..0..0....0..2..2
..1..1..1....2..2..0....0..0..0....0..0..0....0..0..0....0..0..0....2..2..1
..1..1..0....1..1..0....0..2..2....2..2..0....0..0..0....0..1..1....0..0..0
..1..1..0....0..1..1....0..2..2....2..2..2....0..1..1....1..2..2....0..0..0
..1..2..2....0..2..2....0..2..2....2..2..2....1..1..1....2..2..2....2..2..1

Crossrefs

Sequence in context: A332456 A255877 A197277 * A105287 A163349 A016130

Adjacent sequences: A238314 A238315 A238316 * A238318 A238319 A238320

Keyword

nonn

Author

R. H. Hardin, Feb 24 2014

Status

approved