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A249848 Number of length 4+4 0..n arrays with no five consecutive terms having the maximum of any two terms equal to the minimum of the remaining three terms. 1
10, 653, 11052, 92190, 499654, 2029683, 6712760, 19039308, 47942370, 109802473, 232780196, 462822282, 871727454, 1567698415, 2708846832, 4520158424, 7314465594, 11518015365, 17701260700, 26615543606, 39236378742, 56814086571 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 4 of A249844.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

FORMULA

Empirical: a(n) = n^8 + (13/21)*n^7 + (101/30)*n^6 + (71/30)*n^5 + (2/3)*n^4 + 2*n^3 - (1/30)*n^2 + (1/70)*n.

Conjectures from Colin Barker, Aug 18 2017: (Start)

G.f.: x*(10 + 563*x + 5535*x^2 + 15390*x^3 + 14224*x^4 + 4287*x^5 + 311*x^6) / (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>9.

(End)

EXAMPLE

Some solutions for n=4

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

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

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

..0....4....0....3....4....0....0....3....4....0....0....0....0....0....0....4

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

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

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

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

CROSSREFS

Sequence in context: A280897 A099024 A126680 * A214108 A174061 A058174

Adjacent sequences:  A249845 A249846 A249847 * A249849 A249850 A249851

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 07 2014

STATUS

approved

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Last modified May 14 03:33 EDT 2021. Contains 343872 sequences. (Running on oeis4.)