A250337 Number of length 1+5 0..n arrays with every six consecutive terms having the maximum of some three terms equal to the minimum of the remaining three terms.

44, 429, 2056, 6785, 17796, 39949, 80144, 147681, 254620, 416141, 650904, 981409, 1434356, 2041005, 2837536, 3865409, 5171724, 6809581, 8838440, 11324481, 14340964, 17968589, 22295856, 27419425, 33444476, 40485069, 48664504, 58115681

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 + 11*n^2 + 4*n + 1.

Conjectures from Colin Barker, Nov 12 2018: (Start)

G.f.: x*(44 + 165*x + 142*x^2 + 4*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:
..2....6....4....6....3....2....0....3....0....5....4....2....3....6....5....4
..3....3....2....2....0....3....5....1....6....3....1....1....6....1....3....5
..3....6....6....3....3....3....0....6....0....3....2....5....4....5....2....6
..1....5....0....5....1....0....4....1....0....2....2....2....1....4....4....1
..6....5....4....0....0....6....4....3....6....2....1....2....5....4....4....4
..6....0....6....3....1....5....5....5....0....4....2....5....4....4....6....1

Crossrefs

Row 1 of A250336.

Sequence in context: A264555 A231217 A250336 * A002613 A094201 A210426

Adjacent sequences: A250334 A250335 A250336 * A250338 A250339 A250340

Keyword

nonn

Author

R. H. Hardin, Nov 19 2014

Status

approved