a(n) = n! + n^2 + n.

Terms

a(0) =1a(1) =3a(2) =8a(3) =18a(4) =44a(5) =150a(6) =762a(7) =5096a(8) =40392a(9) =362970a(10) =3628910a(11) =39916932a(12) =479001756a(13) =6227020982a(14) =87178291410