OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 1410*a(n-4) for n>6.
Empirical g.f.: 4*x*(86 + 516*x + 3150*x^2 + 19605*x^3 - 1974*x^4 - 513*x^5) / (1 - 1410*x^4). - Colin Barker, Oct 22 2018
EXAMPLE
Some solutions for n=4:
..0..0..1....0..1..1....1..1..2....1..1..1....1..0..0....0..0..0....2..0..2
..2..1..0....0..2..2....1..1..1....1..0..2....0..0..2....1..1..0....0..1..1
..0..1..1....1..1..0....1..2..0....2..1..0....0..2..1....0..1..0....2..1..2
..1..1..1....2..1..2....1..2..1....1..1..2....2..1..0....1..2..2....0..0..1
..2..0..1....1..0..0....1..1..2....2..2..2....1..2..0....0..2..0....2..0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 05 2014
STATUS
approved