a(n) = (n^3 +n)*5^n.

Terms

a(0) =10a(1) =250a(2) =3750a(3) =42500a(4) =406250a(5) =3468750a(6) =27343750a(7) =203125000a(8) =1441406250a(9) =9863281250a(10) =65527343750a(11) =424804687500