OFFSET
1,3
COMMENTS
Column 2 of A217346.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 7*a(n-1) -11*a(n-2) +a(n-3) -a(n-4).
Empirical g.f.: x^2 / (1 - 7*x + 11*x^2 - x^3 + x^4). - Colin Barker, Feb 18 2018
EXAMPLE
All solutions for n=3:
..0..0....1..1....1..1....1..1....1..0....0..1....1..1
..2..2....1..2....2..1....2..2....2..1....1..2....1..1
..1..1....0..1....1..0....0..0....1..1....1..1....1..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Oct 01 2012
STATUS
approved