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A249847
Number of length 3+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, 359, 4064, 25206, 108250, 363349, 1022672, 2522796, 5618202, 11530915, 22141328, 40225250, 69742218, 116180113, 186961120, 291914072, 443818218, 659023455, 958152064, 1366886990, 1916851706, 2646586701, 3602627632
OFFSET
1,1
COMMENTS
Row 3 of A249844.
LINKS
FORMULA
Empirical: a(n) = n^7 + (6/5)*n^6 + 3*n^5 + 3*n^4 + (5/6)*n^3 + (4/5)*n^2 + (1/6)*n.
Conjectures from Colin Barker, Aug 18 2017: (Start)
G.f.: x*(10 + 279*x + 1472*x^2 + 2186*x^3 + 990*x^4 + 103*x^5) / (1 - x)^8.
a(n) = 8*a(n-1) - 28*a(n-2) + 56*a(n-3) - 70*a(n-4) + 56*a(n-5) - 28*a(n-6) + 8*a(n-7) - a(n-8) for n>8.
(End)
EXAMPLE
Some solutions for n=5
..0....1....4....3....1....0....5....1....1....5....5....0....5....4....2....5
..4....5....0....2....4....0....0....2....2....1....3....0....2....4....3....2
..5....1....3....0....0....2....5....4....3....0....0....3....4....0....0....1
..3....4....2....0....0....1....2....1....0....4....4....3....1....0....3....5
..2....2....3....3....2....4....4....4....2....0....2....2....3....2....1....4
..1....1....0....5....4....0....0....5....1....2....0....3....4....2....4....0
..1....2....0....4....2....5....0....3....5....4....5....0....2....3....4....0
CROSSREFS
Sequence in context: A217508 A217509 A016101 * A185255 A160523 A301310
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 07 2014
STATUS
approved