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A250066 Number of length 7+6 0..n arrays with no seven consecutive terms having the maximum of any two terms equal to the minimum of the remaining five terms. 1
21, 21276, 2398187, 81138873, 1329866076, 13468748489, 96884873906, 539919000270, 2469626954391, 9653001714762, 33196888242117, 102660657566831, 290292185100918, 760444039774479, 1864760913276308, 4316829401163980 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 7 of A250059.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..31

FORMULA

Empirical: a(n) = n^13 - (3403/2772)*n^12 + (261607/27720)*n^11 - (14911/2160)*n^10 + (9505/3024)*n^9 + (10147/315)*n^8 - (59251/1260)*n^7 + (112411/5040)*n^6 + (161177/5040)*n^5 - (34699/1080)*n^4 + (17917/1512)*n^3 - (104141/27720)*n^2 + (529/4620)*n.

Empirical g.f.: x*(21 + 20982*x + 2102234*x^2 + 49492727*x^3 + 404433428*x^4 + 1382576034*x^5 + 2163711902*x^6 + 1598287676*x^7 + 544743783*x^8 + 77937032*x^9 + 3687800*x^10 + 27181*x^11) / (1 - x)^14. - Colin Barker, Sep 08 2017

EXAMPLE

Some solutions for n=2

..1....2....1....2....2....1....1....2....0....2....0....0....0....2....2....2

..1....2....0....2....2....1....0....1....2....2....2....2....1....2....2....0

..2....2....0....0....2....1....2....1....1....1....2....1....2....0....2....2

..1....1....2....1....2....0....1....2....2....0....2....1....0....2....0....2

..2....2....2....2....1....0....1....1....0....0....2....2....2....2....1....2

..0....2....2....2....2....2....2....0....1....2....1....1....2....1....2....1

..0....0....1....2....0....2....0....0....1....2....0....0....2....2....2....2

..2....2....2....2....0....1....1....1....0....1....0....0....0....0....0....0

..2....2....2....2....1....2....0....1....2....1....2....2....1....1....2....2

..1....0....0....0....2....2....1....2....2....2....1....1....2....0....2....0

..1....2....2....0....2....2....2....1....2....0....1....2....0....1....0....2

..1....2....2....1....1....1....1....1....0....0....2....2....1....2....2....1

..0....1....2....1....2....2....2....0....1....2....2....2....2....1....1....2

CROSSREFS

Sequence in context: A115485 A172724 A001167 * A299035 A189648 A283841

Adjacent sequences:  A250063 A250064 A250065 * A250067 A250068 A250069

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 11 2014

STATUS

approved

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Last modified October 19 04:40 EDT 2019. Contains 328211 sequences. (Running on oeis4.)