OFFSET
1,1
COMMENTS
Column 6 of A188843.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..200
FORMULA
Empirical: a(n) = (1/720)*n^6 + (17/240)*n^5 + (203/144)*n^4 + (647/48)*n^3 + (2659/45)*n^2 + (1379/20)*n - 143 for n>3.
Empirical g.f.: x*(64 - 71*x - 202*x^2 + 406*x^3 - 174*x^4 - 88*x^5 + 67*x^6 + 6*x^7 - 6*x^8 - x^9) / (1 - x)^7. - Colin Barker, Apr 30 2018
EXAMPLE
Some solutions for 3 X 6:
..1..1..1..1..1..1....1..1..1..1..1..1....0..0..0..1..1..0....1..1..1..1..1..1
..1..1..1..1..1..1....0..0..1..1..1..1....0..0..0..0..1..0....1..1..1..1..0..0
..0..0..1..1..0..1....0..0..0..1..1..0....0..0..0..0..0..0....1..1..0..1..0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 12 2011
STATUS
approved