A249965 Number of length 5+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, 2825, 100236, 1447334, 12123567, 70617807, 317518832, 1176570012, 3753186183, 10625460549, 27293238764, 64668634914, 143140038743, 298924843947, 593647442496, 1128342108536, 2063388866271, 3646247928129

Offset

1,1

Comments

Row 5 of A249960.

Links

R. H. Hardin, Table of n, a(n) for n = 1..147

Formula

Empirical: a(n) = n^10 + (4/45)*n^9 + (31/6)*n^8 + (634/315)*n^7 - (21/20)*n^6 + (761/90)*n^5 - (19/12)*n^4 - (21/10)*n^3 + (119/30)*n^2 - (67/70)*n.

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

G.f.: x*(15 + 2660*x + 69986*x^2 + 497638*x^3 + 1254698*x^4 + 1248320*x^5 + 488690*x^6 + 65078*x^7 + 1715*x^8) / (1 - x)^11.

a(n) = 11*a(n-1) - 55*a(n-2) + 165*a(n-3) - 330*a(n-4) + 462*a(n-5) - 462*a(n-6) + 330*a(n-7) - 165*a(n-8) + 55*a(n-9) - 11*a(n-10) + a(n-11) for n>11.

(End)

Example

Some solutions for n=3:
..3....3....3....1....1....1....3....2....0....2....1....2....1....0....1....0
..2....0....2....2....2....1....3....2....3....0....0....1....1....1....3....0
..2....3....3....0....3....2....0....0....1....0....3....2....0....3....2....3
..0....1....1....2....0....0....3....2....0....2....2....2....3....2....0....2
..0....3....3....2....0....0....0....3....2....1....0....1....3....3....3....2
..2....3....1....0....2....2....3....1....2....2....1....3....0....3....3....3
..3....0....3....3....3....3....3....0....2....3....3....3....1....3....1....0
..3....0....3....1....3....1....2....2....2....0....3....0....2....1....3....0
..3....2....3....0....3....2....1....0....1....3....3....0....2....3....3....3
..3....2....1....1....3....0....2....2....0....0....0....2....0....0....0....1

Crossrefs

Sequence in context: A232407 A208404 A208411 * A108281 A232455 A208579

Adjacent sequences: A249962 A249963 A249964 * A249966 A249967 A249968

Keyword

nonn

Author

R. H. Hardin, Nov 09 2014

Status

approved