Primitive elements of the sequence of integers n such that n divides 2^n + 1 (A006521).

Terms

a(0) =1a(1) =3a(2) =171a(3) =13203a(4) =97641a(5) =354537a(6) =2354697a(7) =10970073a(8) =29884473a(9) =33894369a(10) =38265939a(11) =74214171a(12) =116226009a(13) =344380329a(14) =751611177a(15) =892145817a(16) =2595432537a(17) =4014314433a(18) =10161972027a(19) =11852199369a(20) =13229694441a(21) =22032887841a(22) =22230967347a(23) =22864359897a(24) =24020090001a(25) =26761542921a(26) =27439598619a(27) =27932906619a(28) =37498011939a(29) =166111451217