A249284 Number of length n+3 0..2 arrays with no four consecutive terms having the sum of any three elements equal to three times the fourth

66, 168, 428, 1094, 2792, 7132, 18232, 46616, 119176, 304696, 779066, 1992002, 5093330, 13023126, 33299000, 85142802, 217703012, 556648464, 1423304428, 3639273226, 9305324178, 23792953554, 60836640416, 155554327024, 397739724496

Offset

1,1

Comments

Column 2 of A249290

Links

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

Formula

Empirical: a(n) = a(n-1) +2*a(n-2) +3*a(n-3) +7*a(n-4) +a(n-5) -6*a(n-6) -12*a(n-7) -14*a(n-8) -14*a(n-9) -7*a(n-10) +3*a(n-11) +2*a(n-12)

Example

Some solutions for n=9
..1....0....2....2....1....1....0....1....1....1....0....1....1....2....2....1
..1....0....1....0....0....1....1....0....1....0....0....1....1....0....1....0
..0....1....0....0....2....0....2....2....2....2....0....1....2....0....0....2
..1....0....0....0....2....1....0....2....2....0....2....2....1....0....0....2
..0....1....2....1....0....0....0....0....1....2....2....2....2....1....1....2
..2....0....2....0....0....0....0....1....2....1....0....0....2....0....1....0
..0....1....2....0....0....1....2....0....2....2....2....2....1....0....0....0
..2....1....0....1....1....1....0....1....2....1....0....2....0....1....0....2
..0....0....0....1....2....0....2....0....0....2....2....1....0....0....2....2
..2....0....2....1....2....1....1....0....0....1....1....2....0....2....1....2
..2....0....2....2....1....0....2....0....1....2....2....0....2....0....2....1
..2....2....1....2....2....0....2....1....2....0....1....0....2....0....2....0

Crossrefs

Sequence in context: A043514 A044398 A044779 * A255102 A202647 A202640

Adjacent sequences: A249281 A249282 A249283 * A249285 A249286 A249287

Keyword

nonn

Author

R. H. Hardin, Oct 24 2014

Status

approved