Replace 3^i with n^i in ternary representation of n.

Terms

a(0) =1a(1) =2a(2) =3a(3) =5a(4) =7a(5) =12a(6) =15a(7) =18a(8) =81a(9) =101a(10) =123a(11) =156a(12) =183a(13) =212a(14) =255a(15) =289a(16) =325a(17) =648a(18) =723a(19) =802a(20) =903a(21) =991a(22) =1083a(23) =1200a(24) =1301a(25) =1406a(26) =19683a(27) =21953a(28) =24391a(29) =27030