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A250145 Number of length 6+2 0..n arrays with the medians of every three consecutive terms nondecreasing. 1
111, 2026, 16104, 81664, 311498, 974944, 2637228, 6376143, 14100493, 28998090, 56144452, 103306710, 181980592, 308701712, 506675752, 807775485, 1254955947, 1905142426, 2832649296, 4133191084, 5928550518, 8371971664, 11654349620 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..162

FORMULA

Empirical: a(n) = (1/12)*n^8 + (1487/1260)*n^7 + (4757/720)*n^6 + (13757/720)*n^5 + (4519/144)*n^4 + (21611/720)*n^3 + (2957/180)*n^2 + (2183/420)*n + 1.

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

G.f.: x*(111 + 1027*x + 1866*x^2 + 340*x^3 + 68*x^4 - 80*x^5 + 36*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>10.

(End)

EXAMPLE

Some solutions for n=4:

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

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

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

  2  0  2  2  4  4  0  2  0  3  0  3  2  0  0  2

  2  2  2  3  3  2  1  3  2  1  1  2  2  2  3  3

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

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

  1  3  0  4  3  4  0  3  3  1  3  1  1  4  1  3

CROSSREFS

Row 6 of A250140.

Sequence in context: A303256 A137465 A101152 * A075859 A264466 A302384

Adjacent sequences:  A250142 A250143 A250144 * A250146 A250147 A250148

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 13 2014

STATUS

approved

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Last modified November 28 20:58 EST 2021. Contains 349415 sequences. (Running on oeis4.)