Numbers k such that gcd(sigma(k),k) = k/5.

Terms

a(0) =5a(1) =10a(2) =15a(3) =30a(4) =60a(5) =90a(6) =140a(7) =420a(8) =1170a(9) =2480a(10) =3360a(11) =6200a(12) =7440a(13) =8190a(14) =18600a(15) =40640a(16) =114660a(17) =121920a(18) =131040a(19) =297600a(20) =997920a(21) =2618880a(22) =5059200a(23) =64995840a(24) =72602880a(25) =95472000a(26) =102136320a(27) =167751680a(28) =197308800a(29) =433305600