Returns the Mersenne number 2^n - 1
a = number_mersenne ( n )
a 1x1 matrix of floating point integers, must be positive
a 1x1 matrix of floating point integers
Returns the Mersenne number 2^n - 1.
number_mersenne ( 2 ) // 3 number_mersenne ( 3 ) // 7 number_mersenne ( 5 ) // 31