Numbers k such that phi(k) is a perfect biquadrate.

Terms

a(0) =1a(1) =2a(2) =17a(3) =32a(4) =34a(5) =40a(6) =48a(7) =60a(8) =257a(9) =512a(10) =514a(11) =544a(12) =640a(13) =680a(14) =768a(15) =816a(16) =960a(17) =1020a(18) =1297a(19) =1387a(20) =1417a(21) =1729a(22) =1971a(23) =2109a(24) =2223a(25) =2289a(26) =2331a(27) =2445a(28) =2457a(29) =2565