a(n) = Sum_{p|n, p prime} p^prime(n/p).

Terms

a(0) =0a(1) =4a(2) =9a(3) =8a(4) =25a(5) =59a(6) =49a(7) =128a(8) =243a(9) =2173a(10) =121a(11) =10379a(12) =169a(13) =131415a(14) =180272a(15) =524288a(16) =289a(17) =9982931a(18) =361a(19) =536949037a(20) =129156970a(21) =2147484979a(22) =529a(23) =138601214939a(24) =48828125a(26) =94143178827a(28) =841a(30) =961