OFFSET
1,1
COMMENTS
Row 5 of A200871.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = (1/2520)*n^7 + (17/180)*n^6 + (281/180)*n^5 + (64/9)*n^4 + (4927/360)*n^3 + (2303/180)*n^2 + (604/105)*n + 1.
Conjectures from Colin Barker, Oct 16 2017: (Start)
G.f.: x*(42 + 7*x - 40*x^2 - 55*x^3 + 70*x^4 - 29*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=3
..2....0....1....2....0....3....2....3....2....2....1....0....3....2....0....3
..0....3....1....2....3....3....2....0....3....1....1....0....0....1....0....2
..0....3....3....0....3....2....0....0....3....1....0....0....0....1....1....2
..1....1....3....0....2....2....0....0....3....3....0....2....0....2....1....1
..2....1....3....3....0....1....2....1....0....3....1....2....0....3....0....1
..2....1....3....3....0....1....2....1....0....3....1....2....3....3....0....1
..1....3....1....0....1....1....3....1....0....3....3....3....3....3....0....2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 23 2011
STATUS
approved