OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 98*a(n-1) - 2401*a(n-2) for n>3.
Conjectures from Colin Barker, Jan 21 2019: (Start)
G.f.: 36*x*(1 - x)*(6 - 49*x) / (1 - 49*x)^2.
a(n) = 36 * (49^(n-2) * (240*n+53)) for n>1.
(End)
EXAMPLE
Some solutions for n=2:
..3..0..2..0. .3..1..1..3. .1..3..3..2. .3..2..0..2. .0..0..2..3
..2..0..2..3. .1..3..2..1. .3..3..3..0. .3..0..2..2. .2..2..2..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 21 2016
STATUS
approved