OFFSET
1,1
COMMENTS
Column 2 of A184548.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..200
FORMULA
Empirical: a(n) = (1/24)*n^4 + (3/4)*n^3 + (383/24)*n^2 + (201/4)*n + 22.
Conjectures from Colin Barker, Apr 12 2018: (Start)
G.f.: x*(89 - 252*x + 265*x^2 - 123*x^3 + 22*x^4) / (1 - x)^5.
a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5) for n>5.
(End)
EXAMPLE
Some solutions for 6 X 4:
..0..0..0..0....0..0..0..1....0..0..0..0....0..0..0..1....0..0..0..1
..0..0..0..1....0..0..0..1....0..0..0..1....0..0..0..1....0..0..1..1
..0..0..0..1....0..0..0..1....0..0..0..1....0..0..0..1....0..1..1..1
..0..0..0..1....0..0..0..1....0..0..1..1....0..0..0..1....0..1..1..1
..0..0..1..0....0..0..1..0....0..1..0..0....0..0..0..1....1..1..1..1
..0..1..1..0....0..0..1..1....1..1..0..0....0..0..0..1....1..1..1..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 16 2011
STATUS
approved