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

Terms

a(0) =1a(1) =-3a(2) =-26a(3) =-3a(4) =-3124a(5) =46626a(6) =-823542a(7) =-3a(8) =-26a(9) =9999996872a(10) =-285311670610a(11) =46626a(15) =-3a(17) =46626a(19) =9999996872