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A243727 Number of length n+2 0..8 arrays with no three unequal elements in a row and no three equal elements in a row and new values 0..8 introduced in 0..8 order. 1
3, 6, 12, 25, 53, 116, 259, 594, 1389, 3323, 8095, 20113, 50814, 130632, 341034, 904330, 2432401, 6636002, 18344597, 51376058, 145658087, 417937885, 1212891031, 3558923683, 10552653608, 31606799640, 95575235380, 291651970212 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = 8*a(n-1) - 139*a(n-3) + 196*a(n-4) + 960*a(n-5) - 1827*a(n-6) - 3456*a(n-7) + 7076*a(n-8) + 7239*a(n-9) - 12860*a(n-10) - 9148*a(n-11) + 9072*a(n-12) + 5760*a(n-13).
Empirical g.f.: x*(3 - 18*x - 36*x^2 + 346*x^3 + 99*x^4 - 2696*x^5 + 175*x^6 + 10799*x^7 - 195*x^8 - 22430*x^9 - 4582*x^10 + 19296*x^11 + 9401*x^12) / ((1 - 2*x)*(1 + 2*x)*(1 - 3*x)*(1 - x - x^2)*(1 - x - 3*x^2)*(1 - x - 4*x^2)*(1 - x - 5*x^2)*(1 - x - 8*x^2)). - Colin Barker, Nov 03 2018
EXAMPLE
Some solutions for n=6:
..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
..0....1....0....1....1....1....1....1....0....1....0....1....1....0....0....1
..1....0....1....1....0....0....0....0....1....0....1....0....0....1....1....0
..0....0....1....2....1....0....0....0....0....1....1....0....1....0....1....0
..0....2....2....2....0....1....1....2....0....0....2....1....0....0....0....2
..2....0....1....3....1....0....1....2....1....0....1....0....1....2....1....2
..0....2....1....2....0....1....2....0....1....1....1....1....1....0....0....0
..0....2....3....3....0....0....2....2....0....1....2....1....0....2....0....0
CROSSREFS
Column 8 of A243729.
Sequence in context: A243724 A243725 A243726 * A243728 A243721 A280109
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jun 09 2014
STATUS
approved

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Last modified February 24 11:15 EST 2024. Contains 370303 sequences. (Running on oeis4.)