A207936 Number of n X 6 0..1 arrays avoiding 0 0 1 and 1 0 0 horizontally and 0 0 1 and 1 1 0 vertically.

22, 484, 2706, 9430, 25490, 58602, 120276, 226850, 400646, 671248, 1076902, 1666038, 2498914, 3649382, 5206776, 7277922, 9989270, 13489148, 17950138, 23571574, 30582162, 39242722, 49849052, 62734914, 78275142, 96888872

Offset: 1

Author

R. H. Hardin, Feb 21 2012

Keywords

• nonn

Comments

Column 6 of A207938.

Examples

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

Links

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

Crossrefs

Cf. A207938.

Formula

Empirical: a(n) = 7*a(n-1) - 21*a(n-2) + 35*a(n-3) - 35*a(n-4) + 21*a(n-5) - 7*a(n-6) + a(n-7).

Conjectures from Colin Barker, Jun 26 2018: (Start)

G.f.: 2*x*(11 + 165*x - 110*x^2 - 59*x^3 + 68*x^4 - 15*x^5 + x^6) / (1 - x)^7.

a(n) = (720 - 1584*n - 6206*n^2 + 7335*n^3 + 6505*n^4 + 1089*n^5 + 61*n^6) / 360.

(End)