A207903 Number of nX3 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 0 0 and 0 1 1 vertically.

6, 36, 102, 261, 611, 1278, 2625, 5134, 9798, 18414, 33947, 62049, 112332, 201925, 361298, 643452, 1142526, 2023513, 3576387, 6311690, 11124765, 19589642, 34469830, 60616350, 106548039, 187215857, 328865096, 577561897, 1014154398

Offset: 1

Author

R. H. Hardin Feb 21 2012

Keywords

• nonn

Comments

Column 3 of A207908

Examples

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

Links

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

Formula

Empirical: a(n) = 3*a(n-1) -4*a(n-3) -5*a(n-4) +9*a(n-5) +3*a(n-6) -2*a(n-7) -5*a(n-8) +2*a(n-9) -2*a(n-10) +a(n-11) +a(n-12) +a(n-13) -a(n-14)