OFFSET
1,5
COMMENTS
Row 5 of A187172.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..50
FORMULA
Empirical: a(n) = 100*n^2 - 920*n + 1984 for n>7.
G.f.: 4*x^5*(2 - x)*(2 + 12*x + 18*x^2 + 15*x^3 + 3*x^4) / (1 - x)^3 (conjectured). - Colin Barker, Apr 22 2018
EXAMPLE
Some solutions for 5 X 5:
..1..0..0..0..0....0..0..3..0..0....0..0..0..0..1....0..0..0..0..5
..0..0..0..3..0....2..0..0..0..0....0..0..2..0..0....0..0..4..0..0
..0..2..0..0..0....0..0..0..4..0....3..0..0..0..0....1..0..0..0..0
..0..0..0..0..4....0..1..0..0..0....0..0..0..5..0....0..0..0..3..0
..0..0..5..0..0....0..0..0..0..5....0..4..0..0..0....0..2..0..0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 06 2011
STATUS
approved