Incorrect answer - Mersenne primes

[Caboose700]

Sorry we never replied to the previous thread, the answer posted in that thread was the correct answer.

@Mattio

In the table, p is the exponent and M p is the actual prime number, the 15th number( M p = 21279 - 1) would be the first Mersenne prime exponent over 1000, not the actual prime number which is 386 digits long.