OFFSET
1,1
COMMENTS
Row 6 of A200871.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = (1/20160)*n^8 + (19/720)*n^7 + (211/288)*n^6 + (1889/360)*n^5 + (44167/2880)*n^4 + (15991/720)*n^3 + (5689/336)*n^2 + (391/60)*n + 1.
Conjectures from Colin Barker, Oct 16 2017: (Start)
G.f.: x*(68 + 111*x - 177*x^2 - 167*x^3 + 237*x^4 - 97*x^5 + 35*x^6 - 9*x^7 + x^8) / (1 - x)^9.
a(n) = 9*a(n-1) - 36*a(n-2) + 84*a(n-3) - 126*a(n-4) + 126*a(n-5) - 84*a(n-6) + 36*a(n-7) - 9*a(n-8) + a(n-9) for n>9.
(End)
EXAMPLE
Some solutions for n=3
..3....1....2....1....3....2....1....0....2....2....3....0....3....1....2....2
..3....1....3....3....3....2....3....2....1....2....1....0....3....1....1....0
..0....3....3....3....2....3....3....3....1....1....0....2....3....1....0....0
..0....3....3....3....2....3....1....3....0....1....0....2....2....1....0....0
..2....2....3....1....2....3....0....2....0....1....0....0....1....1....1....1
..3....2....1....0....2....3....0....1....1....1....0....0....0....1....1....2
..3....1....1....0....1....3....2....1....1....0....0....0....0....2....3....2
..3....0....1....2....1....0....2....1....3....0....3....2....0....2....3....2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 23 2011
STATUS
approved