OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = a(n-1) + 3*a(n-2) + 4*a(n-3) + 5*a(n-4) + 3*a(n-5) + 2*a(n-6).
Empirical g.f.: x*(38 + 70*x + 84*x^2 + 85*x^3 + 50*x^4 + 27*x^5) / (1 - x - 3*x^2 - 4*x^3 - 5*x^4 - 3*x^5 - 2*x^6). - Colin Barker, Nov 03 2018
EXAMPLE
Some solutions for n=6:
..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
..1....0....1....1....0....0....1....0....1....1....0....1....0....0....0....1
..0....1....2....1....1....1....0....1....2....2....1....1....1....1....1....2
..1....0....2....2....0....2....2....2....1....0....2....2....0....0....2....0
..1....2....1....1....0....1....1....2....0....1....1....1....0....1....2....2
..1....1....0....0....0....1....2....1....2....2....1....2....2....1....2....2
..1....0....1....2....2....2....1....0....1....0....0....2....0....0....0....0
..0....1....1....2....2....2....1....1....2....1....1....0....0....2....1....0
..0....0....1....1....1....0....0....1....0....2....0....1....1....0....1....1
..1....0....1....0....1....0....2....1....1....0....0....1....0....2....2....2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jun 21 2014
STATUS
approved