a(n) = n^(n-1) + n + 1.

Terms

a(0) =3a(1) =5a(2) =13a(3) =69a(4) =631a(5) =7783a(6) =117657a(7) =2097161a(8) =43046731a(9) =1000000011a(10) =25937424613a(11) =743008370701