OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 27*a(n-1) - 94*a(n-2) + 36*a(n-3) - 4*a(n-4) - 36*a(n-5).
Empirical g.f.: 9*x*(69 - 278*x + 108*x^2 - 16*x^3 - 108*x^4) / (1 - 27*x + 94*x^2 - 36*x^3 + 4*x^4 + 36*x^5). - Colin Barker, Nov 27 2018
EXAMPLE
Some solutions for n=2:
..1..1..2....1..0..2....2..0..0....2..2..2....2..2..0....0..1..0....1..0..0
..0..1..1....2..0..2....0..1..0....1..1..0....1..1..1....2..2..2....0..0..0
..2..2..0....2..0..1....2..2..2....2..1..2....1..1..2....1..0..1....0..2..2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 01 2014
STATUS
approved