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DIY prime magic (Posted on 2012-01-13) Difficulty: 4 of 5
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.

Based on L. E. Card,Patterns in Primes, JRM 1:2, 1968, pp .93-99,

See The Solution Submitted by Ady TZIDON    
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re(2): From the computer -semi-spoiler | Comment 8 of 10 |
(In reply to re: From the computer -semi-spoiler by brianjn)

It is something like 55 hours after executing my program (which was compiled as a C++ EXE, I have had one solution set returned but the program is till running.

With this solution:
 1  1  1  9  7
 1  0  0  0  7
 9  0  0  2  3
 3  7  9  6  3
 9  9  1  3  9
none of the digits within the top two rows have change since my prior post, I'm not sure how much longer I'm prepared to let this run. 

I accidentally 'killed' the program by ordering a computer shut-down but the damage had been done by the time I hit Cancel!  Considering the runtime to the point above (and possible some 8 hours afterwards I'm not going there again.

Edited on January 21, 2012, 7:01 am
  Posted by brianjn on 2012-01-20 18:38:42

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