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A249966 Number of length 6+5 0..n arrays with no six consecutive terms having the maximum of any two terms equal to the minimum of the remaining four terms. 1
15, 4999, 267004, 5207128, 55191061, 389769865, 2062131616, 8794967112, 31750272891, 100377252987, 284840809660, 738995422048, 1777772706385, 4009552754989, 8552986503328, 17379265831600, 33835476742695 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 6 of A249960.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..52

FORMULA

Empirical: a(n) = n^11 - (739/1260)*n^10 + (8033/1260)*n^9 - (517/336)*n^8 + (191/210)*n^7 + (572/45)*n^6 - (247/24)*n^5 + (653/336)*n^4 + (21293/2520)*n^3 - (6337/1260)*n^2 + (37/35)*n.

Conjectures from Colin Barker, Aug 21 2017: (Start)

G.f.: x*(15 + 4819*x + 208006*x^2 + 2329714*x^3 + 9235434*x^4 + 14869326*x^5 + 10156734*x^6 + 2833778*x^7 + 273635*x^8 + 5339*x^9) / (1 - x)^12.

a(n) = 12*a(n-1) - 66*a(n-2) + 220*a(n-3) - 495*a(n-4) + 792*a(n-5) - 924*a(n-6) + 792*a(n-7) - 495*a(n-8) + 220*a(n-9) - 66*a(n-10) + 12*a(n-11) - a(n-12) for n>12.

(End)

EXAMPLE

Some solutions for n=2:

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

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

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

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

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

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

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

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

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

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

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

CROSSREFS

Sequence in context: A191642 A206387 A198903 * A167823 A199099 A251820

Adjacent sequences:  A249963 A249964 A249965 * A249967 A249968 A249969

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 09 2014

STATUS

approved

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Last modified September 25 15:27 EDT 2021. Contains 347658 sequences. (Running on oeis4.)