A255104 Number of length n+5 0..2 arrays with at most one downstep in every 5 consecutive neighbor pairs.

294, 597, 1302, 2951, 6582, 14001, 29147, 61542, 133392, 292534, 634197, 1353282, 2874273, 6149472, 13283988, 28746325, 61881375, 132509427, 283590718, 609038592, 1311917331, 2825639015, 6072583563, 13028913003, 27962048781

Offset

1,1

Comments

Column 5 of A255107.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) -3*a(n-2) +a(n-3) +18*a(n-5) -29*a(n-6) +12*a(n-7) -6*a(n-10) +3*a(n-11).

Empirical g.f.: x*(294 - 285*x + 393*x^2 + 542*x^3 + 1038*x^4 - 3486*x^5 + 1719*x^6 - 129*x^7 - 318*x^8 - 684*x^9 + 441*x^10) / (1 - 3*x + 3*x^2 - x^3 - 18*x^5 + 29*x^6 - 12*x^7 + 6*x^10 - 3*x^11). - Colin Barker, Jan 24 2018

Example

Some solutions for n=4:
..2....0....0....2....1....1....1....0....0....0....2....1....1....0....2....0
..0....0....1....0....2....1....1....0....0....0....2....1....1....1....0....2
..1....0....1....0....0....0....1....1....1....2....1....2....0....1....0....2
..1....0....2....0....1....0....2....0....1....2....1....0....1....2....1....2
..1....1....0....1....1....1....1....1....1....2....1....1....1....2....1....2
..1....1....2....1....1....1....1....1....1....2....1....2....2....2....1....0
..0....0....2....1....1....2....1....1....1....1....1....2....2....0....0....1
..0....0....2....1....0....1....2....2....1....1....2....2....0....1....0....1
..2....2....2....0....0....1....2....2....1....1....2....0....0....1....0....1

Crossrefs

Cf. A255107.

Sequence in context: A153579 A132187 A367207 * A212724 A235948 A250752

Adjacent sequences: A255101 A255102 A255103 * A255105 A255106 A255107

Keyword

nonn

Author

R. H. Hardin, Feb 14 2015

Status

approved