How many a 3x3 magic squares using only the 1st nine noncomposite numbers exist?
There are none. To see why, take the first nine noncomposite numbers (2,3,5,7,11,13,17,19,23) and calculate their total to be 100. Now assume that the common sum for all rows/columns/diagonals is X. The we have 3X=100, but X is the sum of 3 integers. Thus non magic square can exist.

Posted by Daniel
on 20171108 14:01:48 