10^n+7 - Factorizations
Factorizations of numbers of the form 10^n+7 are collected by Makoto Kamada
, continuously up to n=300.
For two reasons I increased my limit to n=10000.
For small n (say n ≤ 400) my aim is to find factors with at least 65 digits using ecm or at least 60 digits using P-1.
For any other n I collect factors of arbitrary length - in the hope that the remaining (large) cofactor is prime.
In this case my intention is to prove its primality using the program primo of Marcel Martin.
information on proven primes.
Sep 15, 2020