The second Jordan totient function applied to the powerful numbers: a(n) = A007434(A001694(n)).

Terms

a(0) =1a(1) =12a(2) =48a(3) =72a(4) =192a(5) =600a(6) =648a(7) =768a(8) =864a(9) =2352a(10) =3072a(11) =3456a(12) =5832a(13) =7200a(14) =7776a(15) =14520a(16) =15000a(17) =12288a(18) =13824a(19) =28392a(20) =28224a(21) =28800a(22) =31104a(23) =43200a(24) =52488a(25) =49152a(26) =55296a(27) =83232a(28) =69984a(29) =115248