Fun with Numbers: The Pan-Prime-Digit Cube Hypothesis

[DavidM]

(08-10-2017 08:17 PM)Werner Wrote:  I change it every day ;-)

I'm currently running with all 5'010'048 order-11 numbers precomputed, that is, all
numbers < 1e11, that, when cubed, have their 11 least significant digits in {2,3,5,7}. ...

Well I just had to ask, didn't I. Interesting approach. The available memory in the 50g wouldn't allow for a very large pool of pre-configured suffixes, I'm afraid. I think I'll start with my original plan, which was to use a Saturn routine to cube/validate the last 5 digits of the current root before proceeding to check the entire root. That will exclude a fairly large percentage of the possible targets (about 98+% I believe). Even with that, I'm thinking a runtime >24hrs is likely.

I bet Claudio could work up a NewRPL version that would find the known root in a few minutes, though.