OFFSET
1,1
COMMENTS
Row 2 of A208392.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 8*a(n-1) + 6*a(n-2) for n>4.
Conjectures from Colin Barker, Jul 02 2018: (Start)
G.f.: x*(1 + x)*(2 - 4*x - 3*x^2) / (1 - 8*x - 6*x^2).
a(n) = ((4-sqrt(22))^n*(-2+sqrt(22)) + (2+sqrt(22))*(4+sqrt(22))^n) / (8*sqrt(22)) for n>2.
(End)
EXAMPLE
Some solutions for n=4:
..0..0..0..0....0..0..0..0....0..1..1..0....0..0..1..2....0..0..0..0
..1..2..2..2....0..1..0..2....1..2..1..2....0..2..2..0....0..1..1..2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 25 2012
STATUS
approved