a(n) = k-th prime, where k = n-th Mersenne prime = A000668(n).

A113936

a(n) = k-th prime, where k = n-th Mersenne prime = A000668(n).

Terms

    a(0) =5a(1) =17a(2) =127a(3) =709a(4) =84011a(5) =1742527a(6) =7754017a(7) =50685770143

External references