A254704 Number of length 6+4 0..n arrays with every five consecutive terms having the maximum of some two terms equal to the minimum of the remaining three terms.

212, 4542, 37204, 183491, 665256, 1961608, 4985336, 11325573, 23567212, 45697586, 83610924, 145721095, 243693152, 393304188, 615444016, 937266185, 1393499844, 2027932966, 2895077444, 4062026571, 5610515416, 7639194608, 10266128040

Offset

1,1

Links

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

Formula

Empirical: a(n) = (73/35)*n^7 + 19*n^6 + 52*n^5 + 60*n^4 + (377/10)*n^3 + 26*n^2 + (199/14)*n + 1.

Conjectures from Colin Barker, Dec 17 2018: (Start)

G.f.: x*(212 + 2846*x + 6804*x^2 + 1163*x^3 - 472*x^4 - 48*x^5 + 8*x^6 - x^7) / (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=4:
..0....1....0....0....1....1....1....2....1....0....2....2....2....1....2....1
..4....4....1....1....2....1....0....1....4....3....2....2....0....2....1....1
..3....4....1....1....1....0....1....1....1....0....2....2....1....2....1....4
..4....2....3....1....1....2....1....2....1....0....2....2....1....4....1....4
..3....2....4....3....1....2....4....0....1....3....1....1....2....4....2....1
..1....2....1....3....2....1....1....3....1....0....3....2....1....2....4....1
..3....3....1....0....1....1....1....1....2....0....3....2....1....2....1....1
..3....0....1....1....0....1....3....1....0....1....2....4....2....1....0....1
..4....2....1....1....1....4....0....1....1....0....2....2....1....3....1....4
..4....2....2....4....4....0....1....2....1....3....1....1....1....2....1....2

Crossrefs

Row 6 of A254698.

Sequence in context: A356358 A232671 A082828 * A267062 A250326 A344423

Adjacent sequences: A254701 A254702 A254703 * A254705 A254706 A254707

Keyword

nonn

Author

R. H. Hardin, Feb 05 2015

Status

approved