Mersenne prime is a number of the form Mn = 2^n − 1 for some prime n. Fermat number is defined as F[n] = 2^n +1 where ‘n’ is a natural number greater than zero, this form is (less commonly) used. The more popular Fermat numbers are defined as F[n] = 2^2^n + 1 where ‘n’ is a natural number greater than or equal to zero. Relations between these types of primes, if any, is useful in research related to prime numbers.