A189258 Number of n X 3 binary arrays without the pattern 0 0 1 diagonally, antidiagonally or horizontally.

7, 49, 280, 1600, 8985, 50397, 282332, 1581428, 8857677, 49611209, 277868792, 1556321080, 8716833601, 48822302485, 273449899316, 1531571519964, 8578212427349, 48045897623297, 269101318957392, 1507215463960672

Offset: 1

Author

R. H. Hardin, Apr 19 2011

Keywords

• nonn

Comments

Column 3 of A189264.

Examples

			Some solutions for 4 X 3:
..1..1..1....0..1..0....1..1..0....0..1..1....1..1..1....0..1..0....1..1..0
..0..0..0....1..1..0....0..0..0....0..1..1....1..0..1....0..1..0....1..1..1
..0..0..0....1..1..1....0..1..1....0..1..1....0..0..0....1..1..1....0..1..1
..0..1..0....0..1..0....1..0..0....1..1..1....1..0..0....1..1..1....1..0..1
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..200

Crossrefs

Cf. A189264.

Formula

Empirical: a(n) = 6*a(n-1) -2*a(n-2) +a(n-4) -50*a(n-5) -6*a(n-6) +140*a(n-7) -56*a(n-8).

Empirical g.f.: x*(7 + 7*x + 18*x^3 - 62*x^4 - 12*x^5 + 132*x^6 - 56*x^7) / (1 - 6*x + 2*x^2 - x^4 + 50*x^5 + 6*x^6 - 140*x^7 + 56*x^8). - Colin Barker, May 01 2018