Mersenne Primes

Mersenne prime's are prime numbers of the form $$2^{n}-1$$, where n is a positive integer.

To date, there have been found just 49 Mersenne primes, and although it has been proven there is a infinite number of normal primes, it is not known if there are a finite number of Mersenne primes. The highest known Mersenne prime is $$2^{74,207,281}-1$$, which was discovered using the |Great Internet Mersenne Prime Search, (GIMPS), by Curtis Cooper of the University of Central Missouri.