The phi-radical numbers: composite numbers m such that rad(phi(m)) = rad(m-1).

Terms

a(0) =1729a(1) =2431a(2) =6601a(3) =9605a(4) =10585a(5) =12801a(6) =15211a(7) =30889a(8) =46657a(9) =69751a(10) =88561a(11) =92929a(12) =105001a(13) =159895a(14) =272323a(15) =368641a(16) =460801a(17) =534061a(18) =610051a(19) =622909a(20) =950797a(21) =992251a(22) =1047619a(23) =1372801a(24) =1374895a(25) =1745701a(26) =1902691a(27) =2210671a(28) =2628073a(29) =2704801