OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - 4*a(n-5) + 6*a(n-6) - 4*a(n-7) + a(n-8) for n>11.
Empirical g.f.: x*(104 - 206*x + 382*x^2 - 304*x^3 + 156*x^4 - 68*x^5 - 28*x^6 + 67*x^7 - 129*x^8 + 103*x^9 - 29*x^10) / ((1 - x)^5*(1 + x)*(1 + x^2)). - Colin Barker, Dec 21 2018
EXAMPLE
Some solutions for n=4:
..0..0..0..0....0..0..0..1....0..1..1..1....0..0..0..1....0..0..0..1
..1..1..1..1....0..0..0..1....1..1..0..0....0..0..0..0....0..0..0..0
..0..0..0..0....0..0..0..1....1..0..0..1....0..0..0..1....0..0..0..0
..1..1..1..1....1..0..0..1....1..1..1..1....1..1..1..1....0..0..0..0
..1..1..0..1....1..1..0..1....1..1..0..0....1..1..0..1....0..0..0..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jun 03 2015
STATUS
approved