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

Terms

a(0) =1a(1) =6a(2) =36a(3) =64a(4) =105a(5) =114a(6) =135a(7) =1980a(8) =2016a(9) =3072a(10) =5120a(11) =7056a(12) =7840a(13) =9216a(14) =16320a(15) =18720a(16) =18900a(17) =23100a(18) =23622a(19) =24003a(20) =25536a(21) =26088a(22) =26733a(23) =28455a(24) =29078a(25) =29337a(26) =29700a(27) =29760a(28) =30597a(29) =30894