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

Terms

a(0) =1a(1) =3a(2) =5a(3) =10a(4) =9a(5) =33a(6) =13a(7) =60a(8) =69a(9) =167a(10) =21a(11) =470a(12) =25a(13) =837a(14) =1245a(15) =1624a(16) =33a(17) =5067a(18) =37a(19) =9570a(20) =13841a(21) =20633a(22) =45a(23) =54612a(24) =12545a(25) =98511a(26) =119601a(27) =201646a(28) =57a(29) =562957