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A243640
Number of length n+2 0..9 arrays with no three unequal elements in a row and new values 0..9 introduced in 0..9 order
1
4, 9, 21, 51, 127, 324, 844, 2243, 6073, 16737, 46905, 133556, 386062, 1132107, 3365627, 10137559, 30920943, 95457177, 298128257, 941574130, 3006037464, 9697650031, 31602766791, 104000078093, 345512414521, 1158493006765
OFFSET
1,1
COMMENTS
Column 9 of A243641
LINKS
FORMULA
Empirical: a(n) = 17*a(n-1) -99*a(n-2) +125*a(n-3) +931*a(n-4) -3185*a(n-5) -1785*a(n-6) +19063*a(n-7) -6754*a(n-8) -56936*a(n-9) +32132*a(n-10) +99764*a(n-11) -41096*a(n-12) -100896*a(n-13) +5152*a(n-14) +42048*a(n-15) +11520*a(n-16)
EXAMPLE
Some solutions for n=5
..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
..1....0....0....1....1....1....0....0....1....0....0....0....0....1....1....1
..0....1....1....1....0....1....0....1....0....1....0....0....1....0....1....0
..1....0....1....1....1....2....0....1....0....0....1....1....0....0....1....0
..1....0....1....1....0....1....0....2....2....0....0....0....0....0....0....0
..1....1....2....0....0....1....0....2....2....0....0....1....2....0....1....0
..2....1....2....1....1....3....1....0....2....2....2....0....0....1....1....0
CROSSREFS
Sequence in context: A243637 A243638 A243639 * A243634 A076861 A374943
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jun 08 2014
STATUS
approved