A new Mersenne prime found by January 1, 2018

Created by JoshuaZ on 2015-05-22; known on 2018-01-01; judged right by JoshuaZ on 2018-01-01.

• JoshuaZ estimated 65% on 2015-05-22
• JoshuaZ   judged this prediction right on 2018-01-01.