a(n) = (n^2 + 1) * 5^n + (n^2 + 2) * 3^n.

Terms

a(0) =3a(1) =19a(2) =179a(3) =1547a(4) =12083a(5) =87811a(6) =605827a(7) =4017787a(8) =25823651a(9) =161789939a(10) =992351123a(11) =5978820331a(12) =35477981011a(13) =207792160483