OFFSET
1,1
COMMENTS
Column 3 of A233129.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 48*a(n-1) - 448*a(n-2) + 1024*a(n-3).
Conjectures from Colin Barker, Mar 19 2018: (Start)
G.f.: x*(3 - 64*x + 192*x^2) / ((1 - 8*x)*(1 - 40*x + 128*x^2)).
a(n) = 8^(-1+n) + ((20-4*sqrt(17))^n*(-3+sqrt(17)) + (3+sqrt(17))*(4*(5+sqrt(17)))^n) / (32*sqrt(17)).
(End)
EXAMPLE
Some solutions for n=4:
..0..1..0....0..1..5....0..1..5....0..1..2....0..1..2....0..1..5....0..1..2
..2..5..2....2..0..4....4..5..2....1..2..1....4..3..5....2..5..2....3..0..1
..0..1..5....5..2..5....0..3..4....3..0..3....2..0..2....0..4..0....1..3..0
..3..5..4....1..5..4....3..1..2....0..3..5....0..3..5....1..0..1....3..4..2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 04 2013
STATUS
approved