a(n) = Sum_{k=1..n} mu(k) * k^k.

Terms

a(0) =1a(1) =-3a(2) =-30a(3) =-30a(4) =-3155a(5) =43501a(6) =-780042a(7) =-780042a(8) =-780042a(9) =9999219958a(10) =-275312450653a(11) =-275312450653