I have the following procedure that has an error:

Can You tell me, where is the mistake?

I'm looking for any procedure to calculate orthogonal latin squares. I found this:

rOrt := proc (A, B, n)

local freq, i, j;

freq := Array(0 .. n^2-1);

for i to n do

for j to n do

freq[A[i][j]+n*B[i][j]] := 1

end do;

end do;

freq := convert(freq, list);

return numboccur(freq, 1)

end proc:

But I don't know what I now have to write to see result, for example for n=3?