Numbers k such that sigma(k)*phi(k) is squarefree.

Terms

a(0) =1a(1) =2a(2) =4a(3) =9a(4) =121a(5) =242a(6) =529a(7) =1058a(8) =2209a(9) =3481a(10) =4418a(11) =5041a(12) =6889a(13) =6962a(14) =10082a(15) =11449a(16) =13778a(17) =17161a(18) =22898a(19) =27889a(20) =32041a(21) =34322a(22) =51529a(23) =55778a(24) =57121a(25) =64082a(26) =96721a(27) =103058a(28) =114242a(29) =120409