A183577 Half the number of nX2 0..3 arrays with each element equal to either the maximum or the minimum of its horizontal and vertical neighbors.

2, 14, 78, 407, 2216, 12024, 65277, 354615, 1926386, 10465655, 56858572, 308906899, 1678265791, 9117888439, 49536803509, 269129777690, 1462162196206, 7943819360442, 43158185018445, 234475238671702, 1273886693818638

Offset: 1

Author

R. H. Hardin Jan 05 2011

Keywords

• nonn

Comments

Column 2 of A183584

Examples

			Some solutions with a(1,1)<=1 for 3X2
..0..0....1..3....1..1....0..2....0..0....1..1....1..0....0..0....1..1....0..0
..0..0....1..3....2..1....0..2....3..0....2..0....1..0....0..0....0..0....2..2
..0..0....1..1....2..2....0..2....3..0....2..0....1..0....1..1....2..2....0..0
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n)=7*a(n-1)-8*a(n-2)+4*a(n-3)-41*a(n-4)+20*a(n-5)-13*a(n-6)+130*a(n-7)+32*a(n-8)+94*a(n-9)-118*a(n-10)-88*a(n-11)-93*a(n-12)-a(n-13)+20*a(n-14)