A184756 Half the number of n X 4 binary arrays with no 1 having an adjacent 1 both above and to its left.

8, 89, 1056, 12397, 145778, 1713803, 20148584, 236878817, 2784890782, 32740859687, 384921344068, 4525368067837, 53202963328218, 625486206737315, 7353594054643744, 86453298151112665, 1016397248157274582

Offset: 1

Author

R. H. Hardin, Jan 21 2011

Keywords

• nonn

Comments

Column 4 of A184761.

Examples

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

Links

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

Crossrefs

Cf. A184761.

Formula

Empirical: a(n) = 8*a(n-1) + 39*a(n-2) + 58*a(n-3) + 32*a(n-4).

Empirical g.f.: x*(8 + 25*x + 32*x^2 + 14*x^3) / (1 - 8*x - 39*x^2 - 58*x^3 - 32*x^4). - Colin Barker, Feb 27 2018