A208082 Number of 7Xn 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 0 and 0 1 0 vertically.

40, 1600, 27880, 572040, 11204720, 223058440, 4412968520, 87523832240, 1734118456440, 34372785484040, 681198922297440, 13500986230325880, 267573654641996120, 5303065945847377120, 105101332133461259960

Offset: 1

Author

R. H. Hardin Feb 23 2012

Keywords

• nonn

Comments

Row 7 of A208078

Examples

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

Links

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

Formula

Empirical: a(n) = 8*a(n-1) +240*a(n-2) +212*a(n-3) -6470*a(n-4) -2816*a(n-5) +58646*a(n-6) +3528*a(n-7) -215345*a(n-8) +36778*a(n-9) +305644*a(n-10) -78492*a(n-11) -174713*a(n-12) +38956*a(n-13) +42650*a(n-14) -5016*a(n-15) -4246*a(n-16) +194*a(n-17) +156*a(n-18) -a(n-20)