A249966 Number of length 6+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.

15, 4999, 267004, 5207128, 55191061, 389769865, 2062131616, 8794967112, 31750272891, 100377252987, 284840809660, 738995422048, 1777772706385, 4009552754989, 8552986503328, 17379265831600, 33835476742695

Offset

1,1

Comments

Row 6 of A249960.

Links

R. H. Hardin, Table of n, a(n) for n = 1..52

Formula

Empirical: a(n) = n^11 - (739/1260)*n^10 + (8033/1260)*n^9 - (517/336)*n^8 + (191/210)*n^7 + (572/45)*n^6 - (247/24)*n^5 + (653/336)*n^4 + (21293/2520)*n^3 - (6337/1260)*n^2 + (37/35)*n.

Conjectures from Colin Barker, Aug 21 2017: (Start)

G.f.: x*(15 + 4819*x + 208006*x^2 + 2329714*x^3 + 9235434*x^4 + 14869326*x^5 + 10156734*x^6 + 2833778*x^7 + 273635*x^8 + 5339*x^9) / (1 - x)^12.

a(n) = 12*a(n-1) - 66*a(n-2) + 220*a(n-3) - 495*a(n-4) + 792*a(n-5) - 924*a(n-6) + 792*a(n-7) - 495*a(n-8) + 220*a(n-9) - 66*a(n-10) + 12*a(n-11) - a(n-12) for n>12.

(End)

Example

Some solutions for n=2:
..2....2....2....1....2....1....2....0....0....1....1....2....1....2....1....2
..2....0....0....1....2....2....0....0....1....2....2....0....1....0....1....0
..2....1....1....1....0....2....1....2....2....2....2....2....2....0....0....0
..0....2....2....0....0....2....2....2....2....1....0....1....2....2....0....2
..1....2....2....0....2....2....0....1....0....2....0....0....2....2....2....1
..2....2....0....2....1....0....2....2....1....2....1....2....2....1....1....2
..2....2....2....2....2....0....2....0....0....1....1....2....0....2....2....1
..2....1....0....2....1....1....2....2....1....2....1....2....1....0....1....0
..0....0....2....1....0....2....1....2....1....2....2....0....0....2....0....0
..0....2....2....2....0....2....2....0....1....1....0....2....1....0....0....1
..2....2....2....1....2....2....0....2....0....2....0....0....2....2....1....1

Crossrefs

Sequence in context: A348816 A206387 A198903 * A167823 A199099 A251820

Adjacent sequences: A249963 A249964 A249965 * A249967 A249968 A249969

Keyword

nonn

Author

R. H. Hardin, Nov 09 2014

Status

approved