Bad luck, there just happens to be no prime number for a long time. The new prime exponent p is 136M, the old largest one was around 82M. So the overall effort

Bad luck, there just happens to be no prime number for a long time. The new prime exponent p is 136M, the old largest one was around 82M. So the overall effort to get from 82 to 136 was around 1.75 times the effort it took from 0 to 82 [calculated as (136/82)^2-1]. So it was more effort to find the 52nd than it was to find all 51 before. See here for the relatively unusual large gap: https://www.mersenne.org/primenet/ https://www.mersenne.org/primenet/