OFFSET
1,4
LINKS
Brendan McKay, Latin squares.
Hugo Pfoertner, Occurrence counts of determinant values of Latin squares for n=1..8, zipped (2019).
EXAMPLE
a(4)=16: There are 2*a(4) = 32 4 X 4 Latin squares with determinant = 0, one of which is
[1 4 3 2]
[4 1 2 3]
[3 2 1 4]
[2 3 4 1].
An example of a 6 X 6 Latin square with determinant = 0 is
[1 3 4 6 5 2]
[3 2 6 5 4 1]
[4 6 3 2 1 5]
[6 5 1 3 2 4]
[5 4 2 1 3 6]
[2 1 5 4 6 3].
CROSSREFS
KEYWORD
nonn,more,hard
AUTHOR
Hugo Pfoertner, Aug 26 2019
STATUS
approved