OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = (7/15)*n^5 + 5*n^4 + 11*n^3 + 8*n^2 + (38/15)*n + 1.
Conjectures from Colin Barker, Nov 10 2018: (Start)
G.f.: x*(28 + 53*x - 10*x^2 - 20*x^3 + 6*x^4 - x^5) / (1 - x)^6.
a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 6*a(n-5) - a(n-6) for n>6.
(End)
EXAMPLE
Some solutions for n=6:
..1....3....4....5....2....1....2....6....6....5....1....2....2....3....2....2
..3....5....3....0....6....0....3....1....3....3....3....2....4....3....4....3
..6....1....1....2....3....1....0....1....2....5....3....1....2....5....5....3
..3....3....3....2....3....1....2....1....3....5....4....2....2....3....4....3
..3....3....4....2....3....1....2....4....3....5....3....2....1....3....1....4
..0....3....3....1....3....2....2....1....5....3....3....5....2....3....4....3
..6....2....2....6....1....0....2....1....1....5....1....1....4....5....6....2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 04 2014
STATUS
approved