This is a magic square of order n=5 by David M. Collison with magic sum S5=65. Embedded in this square is a diamond, which can be viewed as a square, rotated by 45°. The magic sum of the inlaid diamond is S3=39.
7 | 10 | 24 | 15 | 9 |
22 | 1 | 18 | 3 | 21 |
14 | 20 | 13 | 6 | 12 |
5 | 23 | 8 | 25 | 4 |
17 | 11 | 2 | 16 | 19 |