In a 4x4 magic square all rows, columns and the two main diagonals are distinct 4-digit prime numbers when read in either direction.
Create such a square.
Bonus (d4): same for order-5 magic square and 5-digit primes.
L. E. Card,Patterns in Primes, JRM 1:2, 1968, pp .93-99,
(In reply to From the computer -semi-spoiler
4x1, 1x2, 4x3, 2x5,1x7, 1x8 and 3x9 add up to 70, so each of the four rows (or columns) would have to add to 17.5, but that's impossible with integers (digits).
Posted by Charlie
on 2012-01-13 23:33:57