A232049 Number of 3Xn 0..1 arrays with no element less than a strict majority of its horizontal and antidiagonal neighbors.

8, 21, 80, 318, 1315, 5364, 21680, 87452, 352931, 1425261, 5757064, 23253889, 93921193, 379334811, 1532086339, 6187939435, 24992490166, 100942222266, 407695589939, 1646641727295, 6650621491464, 26861196902537, 108489696252447

Offset: 1

Author

R. H. Hardin, Nov 17 2013

Keywords

• nonn

Comments

Row 3 of A232047

Examples

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

Links

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

Formula

Empirical: a(n) = 8*a(n-1) -27*a(n-2) +64*a(n-3) -104*a(n-4) +124*a(n-5) -102*a(n-6) +34*a(n-7) +10*a(n-8) -34*a(n-9) +19*a(n-10) -2*a(n-11) +a(n-12) +10*a(n-13) -2*a(n-14) -2*a(n-15) for n>18