a(n) = (2^prime(n) - 1)*(2^prime(n) + 1) = 2^(2*prime(n)) - 1.
A152099
a(n) = (2^prime(n) - 1)*(2^prime(n) + 1) = 2^(2*prime(n)) - 1.
Terms
- a(0) =15a(1) =63a(2) =1023a(3) =16383a(4) =4194303a(5) =67108863a(6) =17179869183a(7) =274877906943
External references
- oeis: A152099