OFFSET
1,1
COMMENTS
Column 3 of A222462.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 270*a(n-1) - 1547*a(n-2).
Conjectures from Colin Barker, Mar 15 2018: (Start)
G.f.: 7*x*(7 - 41*x) / (1 - 270*x + 1547*x^2).
a(n) = ((135-sqrt(16678))^n*(-5294+41*sqrt(16678)) + (135+sqrt(16678))^n*(5294+41*sqrt(16678))) / (442*sqrt(16678)).
(End)
EXAMPLE
Some solutions for n=3:
..0..0..0....0..0..0....0..0..0....0..0..4....0..0..0....0..0..0....0..0..0
..1..6..3....3..6..3....4..5..2....0..6..0....2..3..4....3..6..1....0..4..6
..2..6..6....6..7..4....5..0..2....6..2..3....7..4..5....5..6..1....4..6..2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 21 2013
STATUS
approved