OFFSET
1,3
COMMENTS
Row 5 of A187377
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..50
FORMULA
Empirical: a(n) = 69*n^2 - 322*n + 372 for n>3.
Empirical G.f.: x^3*(40+68*x+43*x^2-13*x^3)/(1-x)^3. [Colin Barker, Jan 22 2012]
EXAMPLE
Some solutions for 4X4
..0..0..0..0....0..0..0..5....0..4..0..0....0..0..1..0....0..0..0..5
..0..0..5..0....0..0..4..0....3..5..0..0....0..0..2..4....0..2..4..0
..0..4..2..0....1..3..0..0....0..2..0..0....0..0..3..5....0..3..1..0
..0..1..3..0....2..0..0..0....0..0..1..0....0..0..0..0....0..0..0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Mar 09 2011
STATUS
approved