a(n) = the smallest number k such that sigma(k) / phi(k) >= n.

Terms

a(0) =1a(1) =2a(2) =2a(3) =6a(4) =6a(5) =6a(6) =12a(7) =30a(8) =30a(9) =60a(10) =120a(11) =210a(12) =420a(13) =420a(14) =840a(15) =2520a(16) =9240a(17) =9240a(18) =27720a(19) =55440a(20) =120120a(21) =360360a(22) =720720a(23) =2162160a(24) =6126120a(25) =12252240a(26) =36756720a(27) =116396280a(28) =232792560a(29) =698377680