Numbers m that divide 2^k + 1 for some nonnegative k.

Terms

a(0) =1a(1) =2a(2) =3a(3) =5a(4) =9a(5) =11a(6) =13a(7) =17a(8) =19a(9) =25a(10) =27a(11) =29a(12) =33a(13) =37a(14) =41a(15) =43a(16) =53a(17) =57a(18) =59a(19) =61a(20) =65a(21) =67a(22) =81a(23) =83a(24) =97a(25) =99a(26) =101a(27) =107a(28) =109a(29) =113