Each of the letters represent a different integer 0 TO 9 and each row and each column represent a nine digit prime number (18 in all).
C D A E I H D I C
B C C C A C D B F
B G H G D A H J D
F G E C B C A D A
I A D B J F E F C
A G I G F C A B D
D D I G E E A D A
F E E C F E H A C
C D C F D A F D F
(In reply to
For Starters !!! by Syzygy)
54204  Nine Digit Primes?
About one out of every 19 9digit numbers should be prime. Counting up to 110,262,721 (a prime), there are already 556,022 9digit primes.

Posted by Charlie
on 20040824 08:32:29 