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A250085 Number of length 4+5 0..n arrays with every six consecutive terms having the maximum of some two terms equal to the minimum of the remaining four terms. 1
252, 5084, 42936, 222329, 847708, 2623376, 6978064, 16547001, 35852668, 72229740, 137044040, 247259649, 427412636, 712054192, 1148730272, 1801569169, 2755552764, 4121551516, 6042207576, 8698754729, 12318868188, 17185641584 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

FORMULA

Empirical: a(n) = (3/28)*n^8 + (121/35)*n^7 + (85/4)*n^6 + (501/10)*n^5 + (249/4)*n^4 + (1717/30)*n^3 + (1159/28)*n^2 + (1597/105)*n + 1.

Conjectures from Colin Barker, Nov 11 2018: (Start)

G.f.: x*(252 + 2816*x + 6252*x^2 - 2239*x^3 - 2861*x^4 + 56*x^5 + 52*x^6 - 9*x^7 + x^8) / (1 - x)^9.

a(n) = 9*a(n-1) - 36*a(n-2) + 84*a(n-3) - 126*a(n-4) + 126*a(n-5) - 84*a(n-6) + 36*a(n-7) - 9*a(n-8) + a(n-9) for n>9.

(End)

EXAMPLE

Some solutions for n=3:

  3  2  2  0  2  2  3  3  3  2  1  0  1  0  3  1

  0  0  2  2  0  3  3  3  3  2  0  3  1  2  3  1

  2  1  1  2  0  0  3  2  1  0  0  3  3  2  2  1

  3  0  1  0  2  1  0  0  1  3  2  2  1  0  1  1

  2  0  0  0  0  1  0  0  3  2  2  0  1  0  1  3

  2  1  2  0  0  2  0  0  1  2  0  0  2  0  1  3

  2  0  1  1  0  2  2  0  1  2  1  0  1  3  3  0

  3  2  1  3  0  2  1  0  1  2  0  3  2  3  2  1

  0  1  3  1  1  0  0  3  1  2  0  3  3  0  0  3

CROSSREFS

Row 4 of A250081.

Sequence in context: A169713 A099059 A151610 * A024018 A270853 A177301

Adjacent sequences:  A250082 A250083 A250084 * A250086 A250087 A250088

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 11 2014

STATUS

approved

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Last modified December 13 06:26 EST 2019. Contains 329968 sequences. (Running on oeis4.)