Sum of digits of 3^n.

Terms

a(0) =1a(1) =3a(2) =9a(3) =9a(4) =9a(5) =9a(6) =18a(7) =18a(8) =18a(9) =27a(10) =27a(11) =27a(12) =18a(13) =27a(14) =45a(15) =36a(16) =27a(17) =27a(18) =45a(19) =36a(20) =45a(21) =27a(22) =45a(23) =54a(24) =54a(25) =63a(26) =63a(27) =81a(28) =72a(29) =72