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A221456 Number of 0..5 arrays of length n with each element unequal to at least one neighbor, with new values introduced in 0..5 order. 1
0, 1, 2, 7, 25, 102, 455, 2192, 11203, 59814, 329343, 1851911, 10560334, 60776590, 351887190, 2045329031, 11918417465, 69563676328, 406447507101, 2376416054328, 13900548090293, 81332697848104, 475968841105687, 2785759950405621 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,3
COMMENTS
Column 5 of A221459.
LINKS
FORMULA
Empirical: a(n) = 11*a(n-1) - 30*a(n-2) - 21*a(n-3) + 112*a(n-4) + 63*a(n-5) - 119*a(n-6) - 120*a(n-7) - 30*a(n-8).
Empirical g.f.: x^2*(1 - 9*x + 15*x^2 + 29*x^3 - 33*x^4 - 57*x^5 - 19*x^6) / ((1 - x - x^2)*(1 - 2*x - 2*x^2)*(1 - 3*x - 3*x^2)*(1 - 5*x - 5*x^2)). - Colin Barker, Aug 05 2018
EXAMPLE
Some solutions for n=6:
..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
..1....1....1....1....1....1....1....1....1....1....1....1....1....1....1....1
..2....2....0....2....2....1....2....2....0....1....1....2....2....2....0....2
..2....1....0....2....0....0....1....1....2....0....2....2....0....3....2....3
..3....3....2....0....3....0....0....1....1....2....3....1....0....4....0....3
..2....4....3....3....0....2....1....2....0....1....1....3....1....0....2....4
CROSSREFS
Cf. A221459.
Sequence in context: A150510 A150511 A036784 * A221457 A221458 A221453
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 17 2013
STATUS
approved

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Last modified July 19 10:32 EDT 2024. Contains 374392 sequences. (Running on oeis4.)