A231765 Number of (1+1) X (n+1) 0..1 arrays with no element having a strict majority of its horizontal, diagonal and antidiagonal neighbors equal to one.

9, 33, 100, 315, 961, 3024, 9409, 29319, 91204, 284279, 885481, 2758192, 8590761, 26760591, 83356900, 259648623, 808776721, 2519272112, 7847302225, 24443615655, 76139572356, 237167776135, 738755721081, 2301155717168, 7167887098681

Offset: 1

Author

R. H. Hardin, Nov 13 2013

Keywords

• nonn

Examples

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

Links

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

Crossrefs

Row 1 of A231764.

Formula

Empirical: a(n) = 3*a(n-1) + a(n-3) + 7*a(n-4) - 20*a(n-5) - 2*a(n-6) - 4*a(n-8) + 8*a(n-9).

Empirical g.f.: x*(9 + 6*x + x^2 + 6*x^3 - 80*x^4 - 10*x^5 - 8*x^7 + 32*x^8) / ((1 - 3*x - x^2 + 2*x^3)*(1 + x^2 - 6*x^4 - 4*x^6)). - Colin Barker, Oct 01 2018