A251263 Number of (n+1)X(3+1) 0..1 arrays with no 2X2 subblock having x11-x00 less than x10-x01.

57, 313, 1667, 9109, 49872, 273607, 1501739, 8244503, 45265163, 248529844, 1364574377, 7492353561, 41137689397, 225871759293, 1240178072856, 6809359068477, 37387672585765, 205281890979411, 1127126987808309

Offset: 1

Author

R. H. Hardin, Dec 01 2014

Keywords

• nonn

Comments

Column 3 of A251268

Examples

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

Links

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

Formula

Empirical: a(n) = 6*a(n-1) +6*a(n-2) -55*a(n-3) +21*a(n-4) +97*a(n-5) -48*a(n-6) -52*a(n-7) +25*a(n-8) +5*a(n-9) -2*a(n-10)