OFFSET
1,1
COMMENTS
Column 5 of A188843.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..200
FORMULA
Empirical: a(n) = (1/120)*n^5 + (7/24)*n^4 + (89/24)*n^3 + (473/24)*n^2 + (1877/60)*n - 33 for n>2.
Empirical g.f.: x*(32 - 48*x - 20*x^2 + 64*x^3 - 20*x^4 - 12*x^5 + 4*x^6 + x^7) / (1 - x)^6. - Colin Barker, Apr 30 2018
EXAMPLE
Some solutions for 3 X 5:
..1..1..0..0..1....0..1..1..1..1....1..1..1..0..1....1..1..1..1..1
..1..1..0..0..0....0..0..0..0..0....1..1..1..0..0....0..1..0..1..0
..0..1..0..0..0....0..0..0..0..0....1..0..1..0..0....0..0..0..0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 12 2011
STATUS
approved