Numbers k such that the multiplicative order of 2 modulo k is odd.

Terms

a(0) =1a(1) =7a(2) =23a(3) =31a(4) =47a(5) =49a(6) =71a(7) =73a(8) =79a(9) =89a(10) =103a(11) =127a(12) =151a(13) =161a(14) =167a(15) =191a(16) =199a(17) =217a(18) =223a(19) =233a(20) =239a(21) =263a(22) =271a(23) =311a(24) =329a(25) =337a(26) =343a(27) =359a(28) =367a(29) =383