OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 2*a(n-1) + 6*a(n-2) - 12*a(n-3).
Conjectures from Colin Barker, Oct 14 2018: (Start)
G.f.: 2*x*(10 + 3*x - 54*x^2) / ((1 - 2*x)*(1 - 6*x^2)).
a(n) = 2^(2+n) + 2^((-3+n)/2)*3^((-1+n)/2)*(12-12*(-1)^n+5*sqrt(6)+5*(-1)^n*sqrt(6)).
(End)
EXAMPLE
Some solutions for n=5:
0 2 0 0 0 2 2 0 0 0 2 0 0 2 2 0 0 2 0 2
2 2 2 0 1 1 2 2 0 2 2 2 0 0 2 2 2 2 2 2
0 2 2 2 2 0 0 2 0 0 2 0 2 0 2 0 2 0 2 0
0 0 0 2 0 0 2 2 0 2 2 2 1 1 1 1 2 2 1 1
2 0 1 1 2 0 0 2 2 2 0 2 2 0 2 0 0 2 2 0
2 2 0 2 0 0 2 2 2 0 1 1 1 1 1 1 1 1 0 0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 22 2013
STATUS
approved