For what values of
does there exist an
array of entries -1, 0 or 1 such that the
sums obtained by summing the elements of the rows and the columns are all different?
%V0
For what values of $n$ does there exist an $n \times n$ array of entries -1, 0 or 1 such that the $2 \cdot n$ sums obtained by summing the elements of the rows and the columns are all different?
Školjka