All trivial sequences of base 53 for i < 99 are terminated. Just 53^99 is stubborn, it has 3^2 * 5 factors and decreases very slowly. Now at i12 it's a c164 cofactor. It'll take about a week to factor and before the sequence terminates I guess some more will follow.
All nontrivials are done to 110 digits at least.
Since you said that yoyo (is that yoyo@home?) will pick up the nontrivials sooner or later I guess it makes more sense to begin base 2*18^2 instead of continuing with base 53?
Last fiddled with by bur on 20210707 at 14:25
