A243728 Number of length n+2 0..9 arrays with no three unequal elements in a row and no three equal elements in a row and new values 0..9 introduced in 0..9 order

3, 6, 12, 25, 53, 116, 259, 594, 1389, 3323, 8095, 20113, 50814, 130632, 341034, 904331, 2432412, 6636111, 18345401, 51381503, 145690844, 418123477, 1213876444, 3563936878, 10577119368, 31722511379, 96106797203, 294036698701

Offset

1,1

Comments

Column 9 of A243729

Links

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

Formula

Empirical: a(n) = 9*a(n-1) -203*a(n-3) +336*a(n-4) +1869*a(n-5) -4354*a(n-6) -9225*a(n-7) +25044*a(n-8) +27419*a(n-9) -76104*a(n-10) -53277*a(n-11) +119771*a(n-12) +68688*a(n-13) -77292*a(n-14) -45360*a(n-15)

Example

Some solutions for n=6
..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
..1....1....0....1....0....1....0....0....1....1....1....1....0....1....0....0
..1....1....1....0....1....0....1....1....0....0....1....1....1....1....1....1
..2....2....0....1....1....1....1....0....1....0....0....0....1....2....1....0
..1....2....1....0....2....0....2....0....1....1....1....0....2....1....2....1
..2....3....0....0....1....1....1....2....2....1....0....2....2....2....1....1
..2....2....0....1....2....0....2....2....1....0....1....0....3....2....1....0
..0....3....1....1....1....1....2....1....2....1....0....2....2....1....3....0

Crossrefs

Sequence in context: A243725 A243726 A243727 * A243721 A280109 A099445

Adjacent sequences: A243725 A243726 A243727 * A243729 A243730 A243731

Keyword

nonn

Author

R. H. Hardin, Jun 09 2014

Status

approved