OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 4*a(n-1) + a(n-2) - 16*a(n-3) + 4*a(n-4) + 24*a(n-5) - 16*a(n-6).
Empirical g.f.: x*(3 - 5*x - 17*x^2 + 18*x^3 + 32*x^4 - 32*x^5) / ((1 - x)*(1 - 2*x)*(1 - x - 6*x^2 + 8*x^4)). - Colin Barker, Sep 28 2018
EXAMPLE
Some solutions for n=5:
..0..1..1..1..1..2....0..1..0..1..0..0....0..0..1..1..0..0....0..0..1..1..0..0
..0..0..1..1..2..2....1..0..1..0..1..1....0..0..1..1..1..0....0..0..1..1..0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 08 2013
STATUS
approved