Perfect totient numbers, omitting powers of 3.

Terms

a(0) =15a(1) =39a(2) =111a(3) =183a(4) =255a(5) =327a(6) =363a(7) =471a(8) =2199a(9) =3063a(10) =4359a(11) =4375a(12) =5571a(13) =8751a(14) =15723a(15) =36759a(16) =46791a(17) =65535a(18) =140103a(19) =208191a(20) =441027a(21) =4190263a(22) =9056583a(23) =57395631a(24) =172186887a(25) =236923383a(26) =918330183a(27) =3932935775a(28) =4294967295a(29) =4764161215