OFFSET
1,1
COMMENTS
Row 1 of A232076.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 3*a(n-1) + a(n-2) + 4*a(n-3) + 4*a(n-4).
Empirical g.f.: x*(1 + 2*x)*(3 - 2*x^2) / (1 - 3*x - x^2 - 4*x^3 - 4*x^4). - Colin Barker, Mar 19 2018
EXAMPLE
Some solutions for n=7:
..0..1..0..1..0..1..0..0....0..0..1..0..0..0..0..1....0..1..0..0..1..1..1..1
..1..0..1..0..1..1..0..0....0..1..0..1..1..1..1..0....1..0..0..0..1..0..0..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 17 2013
STATUS
approved