A250134 Number of length n+2 0..2 arrays with the medians of every three consecutive terms nondecreasing

27, 67, 162, 391, 900, 2026, 4530, 9975, 21694, 46871, 100571, 214396, 454934, 961550, 2025038, 4252314, 8907731, 18620476, 38854077, 80952643, 168448929, 350130660, 727093383, 1508720630, 3128504906, 6483632727, 13430463741

Offset

1,1

Comments

Column 2 of A250140

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) +9*a(n-3) -15*a(n-4) +7*a(n-5) -22*a(n-6) +18*a(n-7) +a(n-8) +23*a(n-9) +4*a(n-10) -4*a(n-12) -4*a(n-13)

Example

Some solutions for n=6
..0....2....0....1....2....1....0....0....1....0....0....2....1....2....0....1
..0....0....0....2....1....0....2....1....0....2....2....2....0....1....0....0
..1....1....0....1....1....0....2....2....0....2....1....1....1....1....0....0
..2....2....0....1....2....1....0....1....0....2....0....2....1....1....1....0
..0....1....1....1....2....0....2....0....0....2....1....2....1....0....0....0
..2....0....1....2....1....0....2....2....0....2....2....2....2....1....2....1
..2....2....2....2....2....2....0....1....1....2....2....2....0....1....1....0
..1....2....1....0....2....0....2....2....1....1....1....2....2....2....1....2

Crossrefs

Sequence in context: A361147 A099865 A065008 * A116353 A224525 A219130

Adjacent sequences: A250131 A250132 A250133 * A250135 A250136 A250137

Keyword

nonn

Author

R. H. Hardin, Nov 13 2014

Status

approved