Numbers n such that sigma(n) = 15*phi(n) (where sigma=A000203, phi=A000010).

Terms

a(0) =840a(1) =11880a(2) =12180a(3) =25080a(4) =32130a(5) =67830a(6) =79170a(7) =172260a(8) =282744a(9) =312840a(10) =363660a(11) =569160a(12) =596904a(13) =634410a(14) =696696a(15) =843780a(16) =846090a(17) =959310a(18) =996840a(19) =1119690a(20) =1201560a(21) =1402440a(22) =1542840a(23) =1607340a(24) =1929312a(25) =2104440a(26) =2247210a(27) =2363790a(28) =3309240a(29) =3368040