[math-fun] Open problem #6 now solved

In 2005, I published 10 open problems on magic squares in my paper of The Mathematical Intelligencer. One of them (open problem #6) was: Construct a magic square of cubes of prime numbers I am please to announce that this very difficult problem is now solved by a joint work of Jaroslaw Wroblewski (Poland) and Hugo Pfoertner (Germany). Their square is a 42x42 square, and use 1764 consecutive prime numbers: from 11 to 15137. Magic sum = 33151363766492. It remains now 8 unsolved problems on 10. And my €100 prize + bottle of Champagne are still to win! (open problem #2). Christian.