1111111

This number is a composite.

+ 

 
        1 1
       1 1 1
        1 1

A repunit hex-congruent prime in bases 3, 5, and 6. [Dobb]

(There are 3 curios for this number that have not yet been approved by an editor.)

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