OFFSET
1,2
COMMENTS
Row 5 of A221515.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 1*n^4 - 1*n^3 - 10*n^2 + 33*n - 34 for n>3.
Conjectures from Colin Barker, Aug 06 2018: (Start)
G.f.: x^2*(3 + 15*x + 10*x^2 + x^3 - 6*x^4 + 2*x^5 - x^6) / (1 - x)^5.
a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5) for n>8.
(End)
EXAMPLE
Some solutions for n=6:
..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
..3....6....3....6....4....2....3....2....5....4....4....6....2....6....6....2
..5....2....4....2....6....3....3....0....6....1....0....0....0....4....5....3
..4....4....6....6....5....5....0....6....0....0....5....4....4....2....1....6
..6....6....4....4....0....3....4....1....2....5....0....2....0....4....4....0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 18 2013
STATUS
approved