A207713 Number of nX4 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 1 and 1 0 0 vertically.

10, 100, 450, 2205, 11970, 66946, 383845, 2221688, 12947130, 75691595, 443447550, 2600917830, 15265923595, 89639239300, 526483671750, 3092701866155, 18169057652502, 106746028836790, 627171773700111, 3684942718387344

Offset: 1

Author

R. H. Hardin Feb 19 2012

Keywords

• nonn

Comments

Column 4 of A207717

Examples

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

Links

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

Formula

Empirical: a(n) = 8*a(n-1) +6*a(n-2) -138*a(n-3) +52*a(n-4) +850*a(n-5) -487*a(n-6) -2284*a(n-7) +1340*a(n-8) +2858*a(n-9) -1584*a(n-10) -1736*a(n-11) +885*a(n-12) +500*a(n-13) -238*a(n-14) -60*a(n-15) +28*a(n-16) +2*a(n-17) -a(n-18) for n>19