OFFSET
1,1
COMMENTS
Column 8 of A184039.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..53
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*(1225 - 2438*x - 2453*x^2 + 4876*x^3) / ((1 - x)*(1 - 2*x)*(1 - 2*x^2)).
a(n) = 9*2^(n/2-1) + 9*2^(n-1) + 1210 for n even.
a(n) = 9*2^(n-1) + 3*2^((n+1)/2) + 1210 for n odd.
(End)
EXAMPLE
Some solutions for 3 X 9:
..3..0..3..1..3..0..3..1..3....0..0..3..1..3..1..0..0..0
..1..1..1..0..1..1..1..0..1....3..1..0..0..0..0..3..1..3
..3..0..3..1..3..0..3..1..3....0..0..3..1..3..1..0..0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 08 2011
STATUS
approved