OFFSET
1,1
COMMENTS
Column 7 of A217839.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 2*a(n-1) - a(n-2) + a(n-8).
Empirical g.f.: x*(2 + x^2 + x^3 + x^4 + x^5 + x^6 + x^7) / ((1 - x + x^4)*(1 - x - x^4)). - Colin Barker, Jul 23 2018
EXAMPLE
Some solutions for n=8:
..0....0....1....0....0....0....0....0....1....1....0....0....0....0....0....0
..1....1....0....0....0....1....0....0....1....1....0....0....0....0....1....0
..1....1....0....0....1....1....0....1....0....1....1....0....0....0....1....0
..1....1....0....1....0....1....1....1....0....1....1....0....0....1....1....0
..1....1....0....1....0....1....1....0....0....1....1....0....1....1....0....0
..1....1....0....1....0....0....1....0....0....1....0....0....1....0....0....0
..1....0....0....1....0....0....1....0....0....0....0....0....1....0....0....1
..1....0....0....0....0....0....1....0....0....0....0....0....0....0....0....0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Oct 12 2012
STATUS
approved