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A249964
Number of length 4+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, 1593, 37584, 402010, 2662039, 12791191, 48882360, 157381572, 443628615, 1124698773, 2615110872, 5658900702, 11524855615, 22285365715, 41203369552, 73256257608, 125830345119, 209624636913, 339808080960, 537480344226
OFFSET
1,1
COMMENTS
Row 4 of A249960.
LINKS
FORMULA
Empirical: a(n) = n^9 + (107/140)*n^8 + (309/70)*n^7 + (187/45)*n^6 - (43/60)*n^5 + (751/180)*n^4 + (113/60)*n^3 - (1003/630)*n^2 + (193/210)*n.
Conjectures from Colin Barker, Aug 21 2017: (Start)
G.f.: (15 + 1443*x + 22329*x^2 + 96055*x^3 + 145209*x^4 + 81921*x^5 + 15359*x^6 + 549*x^7) / (1 - x)^10.
a(n) = 10*a(n-1) - 45*a(n-2) + 120*a(n-3) - 210*a(n-4) + 252*a(n-5) - 210*a(n-6) + 120*a(n-7) - 45*a(n-8) + 10*a(n-9) - a(n-10) for n>10.
(End)
EXAMPLE
Some solutions for n=3:
..0....1....2....0....2....3....0....2....1....2....1....3....3....2....1....0
..1....1....0....2....0....3....2....2....0....3....1....3....0....1....0....2
..2....3....2....1....0....0....2....3....3....0....3....3....2....1....1....3
..0....0....1....0....3....2....0....0....2....3....2....3....0....0....0....2
..1....2....0....1....3....1....3....0....2....0....0....0....3....0....3....1
..1....0....2....3....2....3....1....2....0....3....0....0....1....2....3....2
..0....1....3....0....2....0....0....3....2....3....3....3....2....1....2....1
..2....1....2....2....0....2....2....2....1....1....3....2....3....3....0....2
..2....3....2....3....0....2....2....1....0....2....1....1....3....3....3....3
CROSSREFS
Sequence in context: A209681 A209682 A209683 * A281801 A208000 A182925
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 09 2014
STATUS
approved