Divisors of 2^40 - 1.

Terms

a(0) =1a(1) =3a(2) =5a(3) =11a(4) =15a(5) =17a(6) =25a(7) =31a(8) =33a(9) =41a(10) =51a(11) =55a(12) =75a(13) =85a(14) =93a(15) =123a(16) =155a(17) =165a(18) =187a(19) =205a(20) =255a(21) =275a(22) =341a(23) =425a(24) =451a(25) =465a(26) =527a(27) =561a(28) =615a(29) =697