a(n) = ceiling((n - sqrt(n))^n).

Terms

a(0) =1a(1) =0a(2) =1a(3) =3a(4) =16a(5) =162a(6) =2004a(7) =29676a(8) =511660a(9) =10077696a(10) =223416176a(11) =5508996067a(12) =149620408779