login
A250065
Number of length 6+6 0..n arrays with no seven consecutive terms having the maximum of any two terms equal to the minimum of the remaining five terms.
1
21, 12284, 915064, 22838540, 295152625, 2461761504, 15032948568, 72725094312, 293743941525, 1027603529940, 3197464381472, 9027047995732, 23478340317185, 56931986760280, 129941488925520, 281314031706000, 581349481570101
OFFSET
1,1
COMMENTS
Row 6 of A250059.
LINKS
FORMULA
Empirical: a(n) = n^12 - (3371/6930)*n^11 + (1655/216)*n^10 - (62/189)*n^9 - (172/63)*n^8 + (7739/315)*n^7 - (717/40)*n^6 - (107/63)*n^5 + (1189/54)*n^4 - (10883/945)*n^3 + (299/630)*n^2 - (3/77)*n.
Conjectures from Colin Barker, Aug 22 2017: (Start)
G.f.: x*(21 + 12011*x + 757010*x^2 + 11894854*x^3 + 66128388*x^4 + 153231228*x^5 + 158628614*x^6 + 73421530*x^7 + 14037031*x^8 + 882297*x^9 + 8616*x^10) / (1 - x)^13.
a(n) = 13*a(n-1) - 78*a(n-2) + 286*a(n-3) - 715*a(n-4) + 1287*a(n-5) - 1716*a(n-6) + 1716*a(n-7) - 1287*a(n-8) + 715*a(n-9) - 286*a(n-10) + 78*a(n-11) - 13*a(n-12) + a(n-13) for n>13.
(End)
EXAMPLE
Some solutions for n=2:
..0....1....0....2....2....0....2....1....2....2....0....2....0....0....1....0
..0....2....1....2....2....2....0....1....2....1....2....2....0....0....2....1
..2....0....2....2....1....1....1....1....0....1....1....0....2....2....1....2
..1....2....1....2....0....2....2....2....2....1....1....2....2....1....0....2
..2....2....0....0....2....1....1....2....2....1....1....1....2....2....1....1
..2....1....2....1....2....2....1....0....2....0....0....0....2....1....2....2
..1....0....2....2....0....0....0....0....1....0....1....1....2....2....0....0
..0....2....0....0....2....0....2....2....2....2....0....1....1....0....2....0
..0....2....2....2....1....2....0....1....0....2....1....2....0....0....2....2
..2....0....1....1....2....2....1....2....0....2....1....0....2....2....2....1
..1....1....2....2....0....2....2....2....1....1....2....2....2....1....0....2
..1....1....0....0....1....2....2....2....1....1....1....1....2....2....1....1
CROSSREFS
Sequence in context: A048914 A046183 A203674 * A180769 A220643 A185557
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 11 2014
STATUS
approved