OFFSET
1,2
COMMENTS
Row 6 of A221515.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 1*n^5 - 20*n^3 + 78*n^2 - 146*n + 125 for n>4.
Conjectures from Colin Barker, Aug 06 2018: (Start)
G.f.: x^2*(5 + 59*x + 73*x^2 + 13*x^3 - 32*x^4 + 9*x^5 - 9*x^6 + 3*x^7 - x^8) / (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>10.
(End)
EXAMPLE
Some solutions for n=6:
..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
..3....2....6....3....2....5....3....2....5....3....2....4....3....6....5....3
..5....0....5....5....6....2....0....2....1....0....4....0....4....6....6....2
..5....1....1....4....5....6....5....0....3....5....0....6....0....1....2....5
..3....5....1....2....2....0....1....4....1....0....1....6....6....3....4....1
..0....1....4....6....5....5....5....6....4....3....6....4....4....0....1....5
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 18 2013
STATUS
approved