Product of divisors of 2^n + 1.

Terms

a(0) =3a(1) =5a(2) =27a(3) =17a(4) =1089a(5) =4225a(6) =16641a(7) =257a(8) =69257922561a(9) =1076890625a(10) =4198401a(11) =16785409a(12) =67125249a(15) =65537a(16) =17180131329a(18) =274878955521