20225

This number is a composite.

+ 2^n + 0^n + 2^n + 2^n + 5^n is a different prime number for n = 0 to 9. 20225 is the smallest positive integer for which this is true. [Gaydos]

Printed from the PrimePages <t5k.org> © G. L. Honaker and Chris K. Caldwell