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

Author

R. H. Hardin, Feb 24 2014

Keywords

• nonn

Comments

Column 2 of A238323

Examples

			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
		

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)