Number of balanced ternary words of length n.

Terms

a(0) =1a(1) =3a(2) =9a(3) =27a(4) =63a(5) =141a(6) =249a(7) =435a(8) =663a(9) =969a(10) =1293a(11) =1713a(12) =2169a(13) =2751a(14) =3333a(15) =4047a(16) =4827a(17) =5733a(18) =6711a(19) =7875a(20) =9081a(21) =10437a(22) =11817a(23) =13425a(24) =15171a(25) =17091a(26) =19017a(27) =21183a(28) =23475a(29) =26001