a(n) = Sum_{d|n} mu(d)*mu(n/d)*d^n.

Terms

a(0) =1a(1) =-5a(2) =-28a(3) =16a(4) =-3126a(5) =47450a(6) =-823544a(7) =0a(8) =19683a(9) =10009766650a(10) =-285311670612a(11) =-2176786432a(15) =0