OFFSET
1,1
COMMENTS
Column 3 of A208050.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 7*a(n-1) - 8*a(n-2) for n>3.
Conjectures from Colin Barker, Mar 06 2018: (Start)
G.f.: 2*x*(1 - x)*(1 - 2*x) / (1 - 7*x + 8*x^2).
a(n) = (2^(-5-n)*((7-sqrt(17))^n*(-13+5*sqrt(17)) + (7+sqrt(17))^n*(13+5*sqrt(17)))) / sqrt(17) for n>1.
(End)
EXAMPLE
Some solutions for n=4:
0 1 0 0 1 0 0 1 2 0 1 0 0 1 2 0 1 0 0 1 2
2 3 2 2 3 1 2 0 3 2 3 1 2 3 0 2 3 1 2 3 0
1 0 1 1 2 0 3 1 2 0 2 0 0 1 3 0 2 3 0 1 2
2 3 2 3 1 2 0 3 1 1 3 1 2 0 1 3 1 2 2 3 1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 22 2012
STATUS
approved