MersennePrimeExponent

MersennePrimeExponent[n] gives the nth Mersenne prime exponent.

Examples

First Mersenne prime exponent:

MersennePrimeExponent[1]
(* 2 *)

First few exponents:

Table[MersennePrimeExponent[n], {n, 1, 5}]
(* {2, 3, 5, 7, 13} *)

Please visit the official Wolfram Language Reference for more details.