A231971 Number of (n+1) X (2+1) 0..1 arrays with no element having a strict majority of its horizontal and vertical neighbors equal to one.

16, 56, 169, 550, 1764, 5680, 18225, 58596, 188356, 605458, 1946025, 6255180, 20106256, 64627982, 207734569, 667725402, 2146283584, 6898841796, 22175081569, 71277802674, 229109651716, 736431677100, 2367126871209, 7608702637640

Offset: 1

Author

R. H. Hardin, Nov 16 2013

Keywords

• nonn

Examples

			Some solutions for n=2:
..0..0..1....1..0..0....0..0..0....0..0..1....0..0..0....0..0..0....0..0..1
..1..0..0....0..0..1....1..0..1....0..0..0....0..0..0....0..1..0....1..0..0
..0..0..0....0..0..0....1..0..0....0..0..0....0..0..0....0..0..0....1..0..0
		

Links

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

Crossrefs

Column 2 of A231977.

Formula

Empirical: a(n) = 3*a(n-1) + 2*a(n-3) + 4*a(n-4) - 10*a(n-5) - 2*a(n-6) - a(n-8) + a(n-9).

Empirical g.f.: x*(16 + 8*x + x^2 + 11*x^3 - 62*x^4 - 14*x^5 + x^6 - 5*x^7 + 6*x^8) / ((1 - 3*x - x^2 + x^3)*(1 + x^2 - 3*x^4 - x^6)). - Colin Barker, Oct 01 2018