OFFSET
1,2
COMMENTS
Column 2 of A233129.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 16*a(n-1) - 48*a(n-2).
Conjectures from Colin Barker, Mar 19 2018: (Start)
G.f.: x*(1 - 8*x) / ((1 - 4*x)*(1 - 12*x)).
a(n) = 2^(2*n-3) * (3^n+3) / 3.
(End)
EXAMPLE
Some solutions for n=5:
..0..1....0..1....0..1....0..1....0..1....0..1....0..1....0..1....0..1....0..1
..1..0....2..5....4..0....4..0....2..0....2..5....4..0....4..0....1..0....1..0
..0..1....0..4....5..2....2..1....0..2....4..3....2..1....5..2....5..2....5..1
..1..5....3..0....3..1....1..3....3..5....5..1....4..5....3..5....3..4....1..2
..0..4....0..2....0..2....2..4....0..4....1..3....0..1....0..2....1..0....0..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 04 2013
STATUS
approved