A231525 Number of 3Xn 0..1 arrays with no element less than a strict majority of its horizontal, diagonal and antidiagonal neighbors.

8, 21, 153, 865, 4665, 25556, 144847, 817539, 4574717, 25577718, 143371820, 804082832, 4506873305, 25254564785, 141534685147, 793277267583, 4446076119277, 24918173471356, 139655004825056, 782709245520654

Offset: 1

Author

R. H. Hardin, Nov 10 2013

Keywords

• nonn

Comments

Row 3 of A231523

Examples

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

Links

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

Formula

Empirical: a(n) = 6*a(n-1) -8*a(n-2) +29*a(n-3) +56*a(n-4) -182*a(n-5) -17*a(n-6) -559*a(n-7) -759*a(n-8) +476*a(n-9) +377*a(n-10) +965*a(n-11) +1048*a(n-12) -43*a(n-13) +15*a(n-14) -384*a(n-15) -335*a(n-16) for n>17