10^n+4^n-1^n.

Terms

a(0) =1a(1) =13a(2) =115a(3) =1063a(4) =10255a(5) =101023a(6) =1004095a(7) =10016383a(8) =100065535a(9) =1000262143a(10) =10001048575a(11) =100004194303