OFFSET
1,1
COMMENTS
Column 2 of A246479.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = a(n-1) + a(n-4).
Empirical g.f.: 2*x*(5 + 2*x + 3*x^2 + 4*x^3) / (1 - x - x^4). - Colin Barker, Mar 19 2018
EXAMPLE
Some solutions for n=6:
..2....0....2....2....1....0....1....0....2....1....2....1....0....0....0....1
..2....0....2....2....0....0....2....0....2....0....1....2....0....1....0....2
..2....0....1....2....0....0....2....1....2....0....2....2....0....0....0....2
..2....0....2....2....0....1....2....0....1....0....2....2....1....0....0....2
..2....0....2....2....0....0....2....0....2....0....2....1....0....0....0....2
..2....0....2....2....0....0....1....0....2....1....2....2....0....0....0....2
..2....0....2....2....0....0....2....0....2....0....2....2....0....0....0....2
..1....0....2....2....1....0....2....0....2....0....1....2....1....1....0....2
..2....0....2....1....0....0....2....0....1....0....2....1....0....0....1....2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Aug 27 2014
STATUS
approved