OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 288*a(n-4) + 1840*a(n-6) + 784*a(n-8).
Empirical g.f.: x*(81 + 356*x + 1566*x^2 + 6954*x^3 + 7585*x^4 + 33960*x^5 + 3136*x^6 + 14112*x^7) / (1 - 288*x^4 - 1840*x^6 - 784*x^8). - Colin Barker, Oct 22 2018
EXAMPLE
Some solutions for n=5:
..0..0....0..1....2..0....1..1....2..1....1..1....1..0....2..0....0..1....1..0
..0..0....2..1....1..1....1..1....1..2....2..2....1..0....0..2....0..0....2..0
..0..1....0..0....0..1....0..2....0..1....1..2....0..2....1..2....0..0....0..0
..1..2....2..2....0..1....1..0....0..0....2..0....0..2....1..1....1..2....0..1
..0..2....1..1....2..2....0..1....0..0....2..0....1..2....2..2....2..2....2..1
..1..1....0..0....0..0....2..0....2..1....2..1....0..1....0..2....0..1....2..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 08 2014
STATUS
approved