Numbers n such that phi(n) = phi(2*n+1).

Terms

a(0) =97a(1) =1417a(2) =2593a(3) =107167a(4) =128137a(5) =262993a(6) =468247a(7) =629821a(8) =879937a(9) =894127a(10) =1100347a(11) =1260847a(12) =1620307a(13) =1644967a(14) =1897417a(15) =2890717a(16) =3122773a(17) =3186397a(18) =3651667a(19) =4169197a(20) =6176467a(21) =7072477a(22) =7344187a(23) =8237707a(24) =8974717a(25) =9254647a(26) =13032547a(27) =15540037a(28) =15673027