Concerns Primes and for which and have a common factor. The only pair with both values less than 400,000 is (17, 3313), with a common factor 112,643.

**References**

Wells, D. G. *The Penguin Dictionary of Curious and Interesting Numbers.* London: Penguin, p. 17, 1986.

© 1996-9

1999-05-26