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A249965 Number of length 5+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, 2825, 100236, 1447334, 12123567, 70617807, 317518832, 1176570012, 3753186183, 10625460549, 27293238764, 64668634914, 143140038743, 298924843947, 593647442496, 1128342108536, 2063388866271, 3646247928129 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 5 of A249960.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..147

FORMULA

Empirical: a(n) = n^10 + (4/45)*n^9 + (31/6)*n^8 + (634/315)*n^7 - (21/20)*n^6 + (761/90)*n^5 - (19/12)*n^4 - (21/10)*n^3 + (119/30)*n^2 - (67/70)*n.

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

G.f.: x*(15 + 2660*x + 69986*x^2 + 497638*x^3 + 1254698*x^4 + 1248320*x^5 + 488690*x^6 + 65078*x^7 + 1715*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:

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

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

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

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

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

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

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

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

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

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

CROSSREFS

Sequence in context: A232407 A208404 A208411 * A108281 A232455 A208579

Adjacent sequences:  A249962 A249963 A249964 * A249966 A249967 A249968

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 09 2014

STATUS

approved

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Last modified February 25 12:28 EST 2021. Contains 341606 sequences. (Running on oeis4.)