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A229016 Number of arrays of median of three adjacent elements of some length 8 0..n array, with no adjacent equal elements in the latter. 1
2, 105, 830, 3527, 10860, 27379, 60180, 119653, 220318, 381749, 629586, 996635, 1524056, 2262639, 3274168, 4632873, 6426970, 8760289, 11753990, 15548367, 20304740, 26207435, 33465852, 42316621, 53025846, 65891437, 81245530, 99456995 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..178

FORMULA

Empirical: a(n) = (11/90)*n^6 + (11/5)*n^5 + (167/36)*n^4 - (43/6)*n^3 + (583/180)*n^2 - (61/30)*n + 1.

Conjectures from Colin Barker, Sep 14 2018: (Start)

G.f.: x*(2 + 91*x + 137*x^2 - 148*x^3 - 4*x^4 + 9*x^5 + x^6) / (1 - x)^7.

a(n) = 7*a(n-1) - 21*a(n-2) + 35*a(n-3) - 35*a(n-4) + 21*a(n-5) - 7*a(n-6) + a(n-7) for n>7.

(End)

EXAMPLE

Some solutions for n=4:

..3....2....3....1....1....0....1....1....1....0....2....4....3....1....1....1

..3....2....3....3....1....1....1....0....2....1....4....2....0....3....2....1

..4....0....2....3....1....3....3....3....2....2....2....2....4....3....2....0

..1....4....3....3....1....3....0....3....2....2....4....1....2....3....1....1

..3....0....3....4....0....4....3....3....2....4....1....2....2....1....0....0

..0....1....3....0....2....2....3....1....0....3....3....1....1....3....1....4

CROSSREFS

Row 6 of A229012.

Sequence in context: A258828 A156880 A280095 * A222840 A260579 A125593

Adjacent sequences:  A229013 A229014 A229015 * A229017 A229018 A229019

KEYWORD

nonn

AUTHOR

R. H. Hardin, Sep 10 2013

STATUS

approved

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Last modified September 27 21:12 EDT 2021. Contains 347698 sequences. (Running on oeis4.)