a(n) is 2^phi(n) times the least common multiple of the proper divisors of n.

Terms

a(0) =1a(1) =2a(2) =2a(3) =4a(4) =8a(5) =16a(6) =24a(7) =64a(8) =64a(9) =192a(10) =160a(11) =1024a(12) =192a(13) =4096a(14) =896a(15) =3840a(16) =2048a(17) =65536a(18) =1152a(19) =262144a(20) =5120a(21) =86016a(22) =22528a(23) =4194304a(24) =6144a(25) =5242880a(26) =106496a(27) =2359296a(28) =114688a(29) =268435456