MC: Ping-Pong Cubes

[ijabbott]

(06-15-2018 03:37 PM)Joe Horn Wrote:  

(06-15-2018 04:52 AM)Werner Wrote:  My understanding is that he offered to produce the next 21-digit Ping Pong Number that is itself a cube, but not of another Ping Pong Number.

Aha, yes, quite right. Valentin handily demonstrated that no Ping-Pong Cube (which he calls a PPN) exists between 381078125 and 10^60.

Even so, the possibility that there are infinitely many of them hasn't been ruled out yet!