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

Terms

a(0) =1a(1) =10a(2) =593a(3) =20412a(4) =268705a(5) =2012174a(6) =10609137a(7) =45136576a(8) =177264449a(9) =774840978a(10) =4486784401a(11) =33739007300a(12) =287589316833