a(n) = Product_{d|n} phi(d).

Terms

a(0) =1a(1) =1a(2) =2a(3) =2a(4) =4a(5) =4a(6) =6a(7) =8a(8) =12a(9) =16a(10) =10a(11) =32a(12) =12a(13) =36a(14) =64a(15) =64a(16) =16a(17) =144a(18) =18a(19) =256a(20) =144a(21) =100a(22) =22a(23) =1024a(24) =80a(25) =144a(26) =216a(27) =864a(28) =28a(29) =4096