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A250064 Number of length 4+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, 4030, 132054, 1800040, 14492075, 82072086, 361440380, 1318262304, 4153110705, 11640299550, 29654571826, 69781269480, 153557285479, 319076606870, 630919231800, 1194629311616, 2177281160205, 3836033915454 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 4 of A250059.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..185

FORMULA

Empirical: a(n) = n^10 + n^9 + (40/7)*n^8 + 7*n^7 - (11/6)*n^6 + (20/3)*n^5 + (25/6)*n^4 - (25/6)*n^3 + (61/42)*n^2.

Conjectures from Colin Barker, Aug 22 2017: (Start)

G.f.: x*(21 + 3799*x + 88879*x^2 + 565631*x^3 + 1296585*x^4 + 1192749*x^5 + 430621*x^6 + 49661*x^7 + 854*x^8) / (1 - x)^11.

a(n) = 11*a(n-1) - 55*a(n-2) + 165*a(n-3) - 330*a(n-4) + 462*a(n-5) - 462*a(n-6) + 330*a(n-7) - 165*a(n-8) + 55*a(n-9) - 11*a(n-10) + a(n-11) for n>11.

(End)

EXAMPLE

Some solutions for n=3:

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

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

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

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

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

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

..3....2....3....3....3....0....3....0....3....3....2....2....3....2....2....2

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

..2....2....2....3....0....2....2....2....2....0....3....0....2....3....3....3

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

CROSSREFS

Sequence in context: A153833 A221164 A264250 * A200998 A209473 A055416

Adjacent sequences:  A250061 A250062 A250063 * A250065 A250066 A250067

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 11 2014

STATUS

approved

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Last modified May 16 22:37 EDT 2022. Contains 353724 sequences. (Running on oeis4.)