OFFSET
1,1
COMMENTS
Column 5 of A255107.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 3*a(n-1) -3*a(n-2) +a(n-3) +18*a(n-5) -29*a(n-6) +12*a(n-7) -6*a(n-10) +3*a(n-11).
Empirical g.f.: x*(294 - 285*x + 393*x^2 + 542*x^3 + 1038*x^4 - 3486*x^5 + 1719*x^6 - 129*x^7 - 318*x^8 - 684*x^9 + 441*x^10) / (1 - 3*x + 3*x^2 - x^3 - 18*x^5 + 29*x^6 - 12*x^7 + 6*x^10 - 3*x^11). - Colin Barker, Jan 24 2018
EXAMPLE
Some solutions for n=4:
..2....0....0....2....1....1....1....0....0....0....2....1....1....0....2....0
..0....0....1....0....2....1....1....0....0....0....2....1....1....1....0....2
..1....0....1....0....0....0....1....1....1....2....1....2....0....1....0....2
..1....0....2....0....1....0....2....0....1....2....1....0....1....2....1....2
..1....1....0....1....1....1....1....1....1....2....1....1....1....2....1....2
..1....1....2....1....1....1....1....1....1....2....1....2....2....2....1....0
..0....0....2....1....1....2....1....1....1....1....1....2....2....0....0....1
..0....0....2....1....0....1....2....2....1....1....2....2....0....1....0....1
..2....2....2....0....0....1....2....2....1....1....2....0....0....1....0....1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 14 2015
STATUS
approved