OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 54*a(n-1) - 182*a(n-2) + 228*a(n-3) + 1152*a(n-4).
Empirical g.f.: 64*x*(51 - 179*x + 246*x^2 + 1152*x^3) / (1 - 54*x + 182*x^2 - 228*x^3 - 1152*x^4). - Colin Barker, Nov 27 2018
EXAMPLE
Some solutions for n=2:
..0..0..2....3..0..0....1..3..2....1..2..0....1..3..0....1..1..3....1..3..0
..1..2..3....3..1..1....0..2..2....2..3..2....0..0..1....0..1..1....0..0..2
..0..0..3....3..0..3....0..1..3....3..3..2....2..1..2....2..1..0....2..3..3
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 01 2014
STATUS
approved