OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 5*a(n-1) - 5*a(n-2) - 3*a(n-3) + 3*a(n-4) + a(n-5).
Empirical g.f.: x*(4 - 10*x - 2*x^2 + 7*x^3 + 2*x^4) / ((1 - x)*(1 - x - x^2)*(1 - 3*x - x^2)). - Colin Barker, Nov 02 2018
EXAMPLE
Some solutions for n=5:
..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
..1....0....1....0....0....1....1....1....0....0....0....1....1....1....1....1
..2....1....2....0....1....2....2....2....1....1....0....2....2....1....1....2
..3....2....2....1....2....0....3....3....2....1....0....3....3....2....2....2
..3....2....1....1....2....3....1....3....0....2....1....0....3....3....2....0
..1....3....0....1....2....3....0....3....3....3....1....0....3....0....0....0
..2....0....3....0....0....2....2....1....1....1....2....1....3....1....1....2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jun 07 2014
STATUS
approved