Number of palindromes of length n in base 3 (A118594).

Terms

a(0) =3a(1) =2a(2) =6a(3) =6a(4) =18a(5) =18a(6) =54a(7) =54a(8) =162a(9) =162a(10) =486a(11) =486a(12) =1458a(13) =1458a(14) =4374a(15) =4374a(16) =13122a(17) =13122a(18) =39366a(19) =39366a(20) =118098a(21) =118098a(22) =354294a(23) =354294a(24) =1062882a(25) =1062882a(26) =3188646a(27) =3188646a(28) =9565938a(29) =9565938