Numbers k such that tau(phi(k)) = rad(k).

Terms

a(0) =1a(1) =4a(2) =36a(3) =54a(4) =96a(5) =200a(6) =448a(7) =1280a(8) =2700a(9) =4500a(10) =5103a(11) =9720a(12) =11264a(13) =14112a(14) =14580a(15) =17280a(16) =26624a(17) =32928a(18) =48000a(19) =54432a(20) =71442a(21) =75000a(22) =81648a(23) =152064a(24) =184320a(25) =187500a(26) =258048a(27) =307200a(28) =350000a(29) =637875