A206996 Number of nX4 0..1 arrays avoiding 0 1 0 horizontally and 0 1 1 vertically.

12, 144, 1011, 6612, 38144, 211471, 1124120, 5856490, 29993573, 152063662, 764940884, 3828258995, 19086321346, 94907855054, 471032090907, 2334592278836, 11559687446670, 57197509727715, 282871139080418, 1398435823681688

Offset: 1

Author

R. H. Hardin Feb 14 2012

Keywords

• nonn

Comments

Column 4 of A207000

Examples

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

Links

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

Formula

Empirical: a(n) = 10*a(n-1) -18*a(n-2) -96*a(n-3) +314*a(n-4) +205*a(n-5) -1435*a(n-6) +363*a(n-7) +2647*a(n-8) -1601*a(n-9) -2021*a(n-10) +1517*a(n-11) +728*a(n-12) -593*a(n-13) -121*a(n-14) +101*a(n-15) +7*a(n-16) -6*a(n-17)