Composite k for which lcm(k, phi(k)) + lcm(k, tau(k)) = lcm(k, sigma(k)).

Terms

a(0) =135a(1) =546a(2) =672a(3) =9585a(4) =24570a(5) =51510a(6) =63855a(7) =190008a(8) =251370a(9) =323730a(10) =372438a(11) =486180a(12) =510570a(13) =723550a(14) =819000a(15) =1058910a(16) =1282365a(17) =1284192a(18) =1356030a(19) =3506390a(20) =5416200a(21) =5604480a(22) =6298625a(23) =15593760a(24) =17813250a(25) =18009000a(26) =20740590a(27) =26759370a(28) =27027000a(29) =27081000