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

1,1

Comments

Row 3 of A232047

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

Example

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

Crossrefs

Sequence in context: A240516 A079386 A156304 * A225658 A226313 A275185

Adjacent sequences: A232046 A232047 A232048 * A232050 A232051 A232052

Keyword

nonn

Author

R. H. Hardin, Nov 17 2013

Status

approved