OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 2*a(n-1) + 21*a(n-2) - 14*a(n-3) - 52*a(n-4) + 12*a(n-5).
Empirical g.f.: 2*x*(23 + 73*x - 106*x^2 - 222*x^3 + 54*x^4) / (1 - 2*x - 21*x^2 + 14*x^3 + 52*x^4 - 12*x^5). - Colin Barker, Nov 29 2018
EXAMPLE
Some solutions for n=4:
..2..2....1..2....0..0....2..2....0..0....1..0....0..1....0..1....0..0....0..2
..1..2....0..2....2..0....1..2....2..0....0..2....2..0....0..1....2..1....0..1
..0..0....2..1....2..1....2..2....1..0....1..0....0..1....0..2....2..2....2..0
..1..2....2..0....1..1....0..1....0..2....2..2....1..1....0..1....1..2....0..1
..1..1....0..1....0..1....2..0....1..2....1..2....1..2....1..1....0..2....0..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 02 2014
STATUS
approved