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A229017 Number of arrays of median of three adjacent elements of some length 9 0..n array, with no adjacent equal elements in the latter. 1
2, 193, 2054, 10735, 38768, 111311, 273124, 597477, 1197190, 2238005, 3954490, 6668675, 10811620, 16948115, 25804712, 38301289, 55586346, 79076233, 110498510, 151939639, 205897208, 275336887, 363754316, 475242125, 614562286, 787223997 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..158

FORMULA

Empirical: a(n) = (5/126)*n^7 + (233/180)*n^6 + (1073/180)*n^5 - (85/18)*n^4 - (89/36)*n^3 + (617/180)*n^2 - (177/70)*n + 1.

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

G.f.: x*(2 + 177*x + 566*x^2 - 405*x^3 - 268*x^4 + 121*x^5 + 8*x^6 - x^7) / (1 - x)^8.

a(n) = 8*a(n-1) - 28*a(n-2) + 56*a(n-3) - 70*a(n-4) + 56*a(n-5) - 28*a(n-6) + 8*a(n-7) - a(n-8) for n>8.

(End)

EXAMPLE

Some solutions for n=4:

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

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

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

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

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

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

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

CROSSREFS

Row 7 of A229012.

Sequence in context: A260404 A064682 A139949 * A103429 A316901 A316888

Adjacent sequences:  A229014 A229015 A229016 * A229018 A229019 A229020

KEYWORD

nonn

AUTHOR

R. H. Hardin, Sep 10 2013

STATUS

approved

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Last modified February 20 13:40 EST 2020. Contains 332077 sequences. (Running on oeis4.)