OFFSET
1,1
COMMENTS
Column 3 of A184048.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..200
FORMULA
Empirical: a(n) = 3*a(n-1) - 6*a(n-3) + 4*a(n-4).
Conjectures from Colin Barker, Apr 10 2018: (Start)
G.f.: x*(25 - 44*x - 52*x^2 + 88*x^3) / ((1 - x)*(1 - 2*x)*(1 - 2*x^2)).
a(n) = 3*2^(n/2) + 2^(n+1) + 17 for n even.
a(n) = 2^(n+1) + 2^((n+3)/2) + 17 for n odd.
(End)
EXAMPLE
Some solutions for 5 X 4:
..2..1..2..1....0..2..0..2....2..2..2..0....1..1..1..1....0..2..0..2
..0..2..0..2....1..1..1..1....0..0..0..2....2..1..2..1....2..0..2..0
..1..2..1..2....2..0..2..0....2..2..2..0....1..1..1..1....0..2..0..2
..0..2..0..2....1..1..1..1....0..0..0..2....2..1..2..1....2..0..2..0
..1..2..1..2....2..0..2..0....2..2..2..0....1..1..1..1....2..0..2..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 08 2011
STATUS
approved