OFFSET
1,1
COMMENTS
Row 2 of A256816.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = (1/120)*n^5 + (1/24)*n^4 + (3/8)*n^3 - (1/24)*n^2 + (277/60)*n + 3.
Empirical g.f.: x*(8 - 32*x + 56*x^2 - 48*x^3 + 20*x^4 - 3*x^5) / (1 - x)^6. - Colin Barker, Jan 21 2018
EXAMPLE
Some solutions for n=4:
..0....0....1....0....0....0....1....1....0....0....1....0....0....1....0....0
..0....0....1....0....0....1....0....1....1....0....0....1....1....1....0....1
..0....1....1....1....1....0....0....1....0....0....0....0....1....0....0....0
..0....0....1....0....0....0....1....0....1....1....0....1....0....0....0....0
..0....1....0....0....0....1....1....0....1....0....1....0....1....0....0....1
..1....1....0....1....0....1....1....0....0....1....1....1....1....0....0....0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 10 2015
STATUS
approved