OFFSET
1,2
COMMENTS
Row 5 of A215190.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 3*a(n-1) - a(n-2) - 4*a(n-3) + 2*a(n-4) + 2*a(n-5) + 2*a(n-6) - 4*a(n-7) - a(n-8) + 3*a(n-9) - a(n-10).
Empirical g.f.: 6*x^2*(5 + 21*x + 56*x^2 + 69*x^3 + 57*x^4 + 24*x^5 + 8*x^6) / ((1 - x)^6*(1 + x)^2*(1 + x + x^2)). - Colin Barker, Jul 22 2018
EXAMPLE
Some solutions for n=6:
..5....5....3....4....6....0....6....6....3....2....1....6....2....0....3....2
..6....3....2....1....4....4....1....5....1....6....5....1....1....1....2....6
..4....2....5....3....5....1....0....4....3....4....6....3....3....2....5....5
..1....1....2....0....0....5....2....1....2....3....4....2....2....0....1....2
..2....0....0....5....6....2....1....5....0....2....1....6....5....4....4....1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Aug 05 2012
STATUS
approved