Numbers n such that sigma(tau(phi(n))) = tau(phi(sigma(n))) = phi(sigma(tau(n))).

Terms

a(0) =1a(1) =34a(2) =36a(3) =96a(4) =128a(5) =468a(6) =1200a(7) =21216a(8) =102060a(9) =110976a(10) =117684a(11) =211428a(12) =331380a(13) =366660a(14) =437220a(15) =511680a(16) =530712a(17) =706560a(18) =710388a(19) =726240a(20) =732240a(21) =759360a(22) =838080a(23) =845376a(24) =875840a(25) =911040a(26) =975936a(27) =1014016a(28) =1041216a(29) =1093440