a(n) = 5^n + 8^n + 9^n.

Terms

a(0) =3a(1) =22a(2) =170a(3) =1366a(4) =11282a(5) =94942a(6) =809210a(7) =6958246a(8) =60214562a(9) =523591342a(10) =4570291850a(11) =40019822326a(12) =351393153842