Numbers k such that phi(k) and sigma(k) are both perfect squares.

Terms

a(0) =1a(1) =170a(2) =364a(3) =679a(4) =5044a(5) =5130a(6) =5670a(7) =5770a(8) =8721a(9) =8736a(10) =9154a(11) =9639a(12) =9809a(13) =14322a(14) =16376a(15) =22413a(16) =27783a(17) =30256a(18) =32025a(19) =37114a(20) =38760a(21) =51455a(22) =71604a(23) =78570a(24) =82615a(25) =88392a(26) =92004a(27) =100821a(28) =101153a(29) =104168