OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 11*a(n-1) - 39*a(n-2) + 21*a(n-3) + 151*a(n-4) - 217*a(n-5) - 181*a(n-6) + 339*a(n-7) + 130*a(n-8) - 154*a(n-9) - 60*a(n-10).
Empirical g.f.: x*(4 - 35*x + 78*x^2 + 87*x^3 - 408*x^4 - 16*x^5 + 668*x^6 + 57*x^7 - 368*x^8 - 120*x^9) / ((1 - x)*(1 + x)*(1 - 2*x)*(1 - 3*x)*(1 - 2*x - x^2)*(1 - 2*x - 2*x^2)*(1 - 2*x - 5*x^2)). - Colin Barker, Nov 02 2018
EXAMPLE
Some solutions for n=6:
..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
..1....1....0....1....1....0....0....0....1....1....1....1....1....1....1....1
..1....0....1....1....1....1....0....1....1....1....1....0....0....1....1....1
..2....0....1....0....1....0....1....1....1....1....2....0....1....2....0....0
..1....1....1....0....0....0....1....0....2....2....2....1....1....2....0....1
..2....1....1....0....1....1....2....1....2....2....2....0....0....2....2....1
..2....2....2....0....0....0....2....0....1....2....3....0....0....1....0....1
..1....2....2....1....0....0....0....0....1....1....2....2....2....2....0....2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jun 08 2014
STATUS
approved