A250082 Number of length 1+5 0..n arrays with every six consecutive terms having the maximum of some two terms equal to the minimum of the remaining four terms.

49, 444, 2086, 6835, 17871, 40054, 80284, 147861, 254845, 416416, 651234, 981799, 1434811, 2041530, 2838136, 3866089, 5172489, 6810436, 8839390, 11325531, 14342119, 17969854, 22297236, 27420925, 33446101, 40486824, 48666394, 58117711

Offset

1,1

Links

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

Formula

Empirical: a(n) = 3*n^5 + 10*n^4 + 15*n^3 + (27/2)*n^2 + (13/2)*n + 1.

Conjectures from Colin Barker, Nov 10 2018: (Start)

G.f.: x*(49 + 150*x + 157*x^2 - x^3 + 6*x^4 - x^5) / (1 - x)^6.

a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 6*a(n-5) - a(n-6) for n>6.

(End)

Example

Some solutions for n=6:
..5....0....3....0....2....3....3....4....3....4....5....6....5....3....1....6
..6....3....1....6....6....0....1....6....5....2....6....5....6....3....5....4
..5....1....1....6....3....6....3....4....5....2....4....2....4....2....1....6
..1....1....2....6....6....0....1....3....3....6....2....4....0....4....1....6
..3....1....6....2....5....3....1....4....5....1....2....6....5....2....2....4
..3....5....0....2....3....0....0....4....3....4....2....4....4....1....3....0

Crossrefs

Row 1 of A250081.

Sequence in context: A063874 A063132 A250081 * A012097 A218594 A263706

Adjacent sequences: A250079 A250080 A250081 * A250083 A250084 A250085

Keyword

nonn

Author

R. H. Hardin, Nov 11 2014

Status

approved