a(n) = Sum_{k=1..n} phi(gcd(k, n))^(n/gcd(k, n)).

Terms

a(0) =1a(1) =2a(2) =4a(3) =5a(4) =8a(5) =10a(6) =12a(7) =14a(8) =28a(9) =28a(10) =20a(11) =62a(12) =24a(13) =54a(14) =272a(15) =68a(16) =32a(17) =198a(18) =36a(19) =676a(20) =1224a(21) =130a(22) =44a(23) =1348a(24) =4136a(25) =180a(26) =3540a(27) =3426a(28) =56a(29) =12632