Related to hyperperfect numbers of a certain form.
From Daniel Minoli (daniel.minoli(AT)ses.com), Aug 27 2009: (Start)
Minoli defined the sequences and concepts that follow in the 1980 IEEE paper below:
 For t=2 to infinity, the sequence m(n,t) = n exp(t)  (n1) is called a Mersenne Sequence Rooted on n
 If n is prime, this sequence is called a Legitimate Mersenne Sequence
 Any j belonging to the sequence m(n,t) is called a Generalized Mersenne Number (nGMN)
 If j belonging to the sequence m(n,t) is prime, it is then called a nGeneralized Mersenne Prime (nGMP).
Note: m(n,t) = n*m(n,t1) + n exp(2)  2*n+1.
These numbers play a role in the context of hyperperfect numbers.
(End)
The next terms are > 4000.  Vincenzo Librandi, Sep 27 2012
a(7)=21689 and a(8)=25679 correspond to probable primes, found with Dario Alpern's factorization tool using the elliptic curve method; no more terms < 35000.  Andrej Jakobcic, Feb 17 2019
