OFFSET
1,2
COMMENTS
Row 1 of A267911.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 3*a(n-1) + 2*a(n-2) - 8*a(n-3) for n>5.
Conjectures from Colin Barker, Feb 25 2018: (Start)
G.f.: x*(1 - x - 4*x^2 + 3*x^3 + 4*x^4) / ((1 - 2*x)*(1 - x - 4*x^2)).
a(n) = (1/17)*2^(-5-n)*(-17*4^(1+n) + (85-19*sqrt(17))*(1-sqrt(17))^n + (1+sqrt(17))^n*(85+19*sqrt(17))) for n>2.
(End)
EXAMPLE
Some solutions for n=8:
..0..1..1..2..0..1..2..0....0..1..2..0..2..0..1..0....0..1..2..0..0..1..0..2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 22 2016
STATUS
approved