a(n) = (n^3 + n^2)*5^n.

Terms

a(0) =0a(1) =10a(2) =300a(3) =4500a(4) =50000a(5) =468750a(6) =3937500a(7) =30625000a(8) =225000000a(9) =1582031250a(10) =10742187500a(11) =70898437500a(12) =457031250000