A243639 Number of length n+2 0..8 arrays with no three unequal elements in a row and new values 0..8 introduced in 0..8 order

4, 9, 21, 51, 127, 324, 844, 2243, 6073, 16737, 46905, 133556, 386062, 1132107, 3365627, 10137558, 30920924, 95456942, 298125982, 941555265, 3005897555, 9696696210, 31596681866, 103963289341, 345299662267, 1157307776719

Offset

1,1

Comments

Column 8 of A243641

Links

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

Formula

Empirical: a(n) = 15*a(n-1) -76*a(n-2) +78*a(n-3) +554*a(n-4) -1518*a(n-5) -1000*a(n-6) +6492*a(n-7) -505*a(n-8) -13105*a(n-9) +2036*a(n-10) +13670*a(n-11) +672*a(n-12) -5632*a(n-13) -1680*a(n-14)

Example

Some solutions for n=5
..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
..0....1....1....1....0....0....1....1....1....0....1....1....1....0....1....1
..1....1....1....1....1....1....1....1....0....0....0....0....0....0....0....1
..0....1....2....0....1....1....0....1....1....0....0....0....0....1....0....1
..0....2....1....0....2....1....0....1....1....0....1....2....0....1....0....0
..1....2....1....0....2....2....1....1....1....1....1....2....2....2....2....0
..0....2....2....2....3....2....1....2....0....0....2....1....2....1....0....1

Crossrefs

Sequence in context: A243636 A243637 A243638 * A243640 A243634 A076861

Adjacent sequences: A243636 A243637 A243638 * A243640 A243641 A243642

Keyword

nonn

Author

R. H. Hardin, Jun 08 2014

Status

approved