a(n) = Sum_{d|n} phi(d^tau(d)).

Terms

a(0) =1a(1) =3a(2) =7a(3) =35a(4) =21a(5) =441a(6) =43a(7) =2083a(8) =493a(9) =4023a(10) =111a(11) =995801a(12) =157a(13) =16509a(14) =27027a(15) =526371a(16) =273a(17) =11338335a(18) =343a(19) =25604055a(20) =111181a(21) =106593a(22) =507a(23) =36692769241a(24) =12521a(25) =211071a(26) =354787a(27) =206540957a(28) =813a(29) =174960031461