9

This number is a composite.

Single Curio View:   (Seek other curios for this number)
The smallest composite number n such that both 2n+n and 2n-n are prime. That is, 29+9 = 521 and 29-9 = 503 are prime. [Poo Sung]

Submitted: 2009-06-03 02:02:59;   Last Modified: 2009-06-03 05:56:56.
Printed from the PrimePages <primes.utm.edu> © G. L. Honaker and Chris K. Caldwell