Earliest sequence where a(a(n))=3^n.

Terms

a(0) =2a(1) =3a(2) =9a(3) =5a(4) =81a(5) =7a(6) =729a(7) =10a(8) =27a(9) =6561a(10) =12a(11) =177147a(12) =14a(13) =1594323a(14) =16a(15) =14348907a(16) =18a(17) =129140163a(18) =20a(19) =1162261467a(20) =22a(21) =10460353203a(22) =24a(23) =94143178827a(24) =26a(25) =847288609443a(26) =19683a(27) =29a(29) =31a(31) =33