(2^(2p - 1)/2)-1, where p is prime.

A139289

(2^(2p - 1)/2)-1, where p is prime.

Terms

    a(0) =3a(1) =15a(2) =255a(3) =4095a(4) =1048575a(5) =16777215a(6) =4294967295a(7) =68719476735

External references