OFFSET
1,1
COMMENTS
Column 4 of A188105.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..200
FORMULA
Empirical: a(n)=2*a(n-1)-a(n-2)+a(n-4)-2*a(n-5)+a(n-6)+a(n-8)-a(n-9) for n>14.
Empirical g.f.: x*(3594 - 6545*x + 3729*x^2 + 1142*x^3 - 3818*x^4 + 5473*x^5 - 4061*x^6 - 1134*x^7 - 3342*x^8 + 4191*x^9 + 74*x^10 - 492*x^11 + 448*x^12 + 625*x^13) / ((1 - x)*(1 - x - x^4 + x^5 - x^8)). - Colin Barker, Feb 07 2018
EXAMPLE
Some solutions for 5 X 7:
..0..0..0..0..1..0..0....0..0..0..0..0..0..0....0..0..0..0..0..0..0
..0..0..0..0..0..1..0....0..0..0..0..0..0..1....0..0..0..0..0..1..0
..0..0..0..0..0..0..1....0..0..0..0..0..0..1....0..0..0..0..0..0..0
..0..0..0..0..0..0..0....0..0..0..0..0..0..0....0..0..0..0..0..0..0
..0..0..0..0..0..0..0....1..0..0..0..0..0..0....0..0..0..0..0..0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 20 2011
STATUS
approved