OFFSET
1,1
COMMENTS
Row 4 of A200251.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 2*a(n-1) - 2*a(n-3) + 3*a(n-4) - 4*a(n-5) + 4*a(n-7) - 3*a(n-8) + 2*a(n-9) - 2*a(n-11) + a(n-12).
Empirical g.f.: x*(8 + 8*x + 21*x^2 + 13*x^3 + 21*x^4 + 12*x^5 + 13*x^6 - 2*x^7 + 3*x^8 - 2*x^10 + x^11) / ((1 - x)^5*(1 + x)^3*(1 + x^2)^2). - Colin Barker, Feb 23 2018
EXAMPLE
Some solutions for n=6:
..4....4....0....1....2....0....1....4....0....1....3....2....1....3....2....2
..4....6....2....1....6....1....6....5....0....3....5....2....1....6....6....6
..6....5....5....6....1....2....0....6....2....5....1....5....6....3....2....4
..1....6....3....6....2....4....3....3....5....5....3....4....5....6....3....6
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 15 2011
STATUS
approved