a(n) = Sum_{d|n} d^d * binomial(n/d-1,d-1).

Terms

a(0) =1a(1) =1a(2) =1a(3) =5a(4) =1a(5) =9a(6) =1a(7) =13a(8) =28a(9) =17a(10) =1a(11) =102a(12) =1a(13) =25a(14) =163a(15) =285a(16) =1a(17) =303a(18) =1a(19) =1061a(20) =406a(21) =41a(22) =1a(23) =3172a(24) =3126a(25) =49a(26) =757a(27) =5173a(28) =1a(29) =16654