A232048 Number of 2 X n 0..1 arrays with no element less than a strict majority of its horizontal and antidiagonal neighbors.

4, 7, 15, 34, 79, 184, 426, 984, 2274, 5258, 12159, 28117, 65018, 150347, 347661, 803931, 1859013, 4298789, 9940535, 22986529, 53154136, 122913828, 284226412, 657246261, 1519818815, 3514434954, 8126793100, 18792428087, 43455684079

Offset: 1

Author

R. H. Hardin, Nov 17 2013

Keywords

• nonn

Examples

			Some solutions for n=7:
..1..1..1..1..0..0..0....1..1..1..0..0..0..1....0..0..0..0..0..1..0
..0..0..0..0..0..1..1....0..0..0..0..0..0..0....0..0..0..0..0..0..0
		

Links

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

Crossrefs

Row 2 of A232047.

Formula

Empirical: a(n) = 4*a(n-1) - 6*a(n-2) + 7*a(n-3) - 6*a(n-4) + 3*a(n-5) - a(n-6) - a(n-7) for n>8.

Empirical g.f.: x*(4 - 9*x + 11*x^2 - 12*x^3 + 8*x^4 - 3*x^5 - x^6 + x^7) / ((1 - x + x^2)*(1 - 3*x + 2*x^2 - 2*x^3 + 2*x^4 + x^5)). - Colin Barker, Oct 02 2018