a(n) = round((n+1/4)^n).

Terms

a(0) =1a(1) =5a(2) =34a(3) =326a(4) =3988a(5) =59605a(6) =1052849a(7) =21460092a(8) =495764693a(9) =12800845442a(10) =365323615365