A250735 Number of (6+1)X(n+1) 0..1 arrays with nondecreasing x(i,j)+x(i,j-1) in the i direction and nondecreasing min(x(i,j),x(i-1,j)) in the j direction.

166, 350, 942, 2434, 6016, 14437, 34069, 79704, 185684, 431691, 1002869, 2329047, 5409245, 12563824, 29186388, 67808124, 157558290, 366127187, 850864580, 1977462106, 4595987342, 10682199696, 24828823703, 57710916319, 134142923156

Offset: 1

Author

R. H. Hardin, Nov 27 2014

Keywords

• nonn

Comments

Row 6 of A250729

Examples

			Some solutions for n=4
..0..0..0..0..0....0..0..0..0..1....0..0..0..0..1....0..0..0..1..1
..0..0..0..0..0....0..0..0..0..1....0..0..0..1..0....0..0..0..1..1
..0..0..0..0..0....0..0..0..0..1....1..0..1..0..1....0..0..1..1..1
..0..0..0..1..1....1..0..0..0..1....0..1..0..1..1....0..0..1..1..1
..0..0..0..1..1....0..1..1..1..1....1..0..1..1..1....0..0..1..1..1
..0..0..1..1..1....0..1..1..1..1....0..1..1..1..1....0..0..1..1..1
..0..1..1..1..1....0..1..1..1..1....1..1..1..1..1....1..1..1..1..1
		

Links

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

Formula

Empirical: a(n) = 6*a(n-1) -8*a(n-2) -19*a(n-3) +61*a(n-4) -32*a(n-5) -70*a(n-6) +104*a(n-7) -30*a(n-8) -30*a(n-9) +24*a(n-10) -5*a(n-11) for n>15