a(n) = 3^n - A006952(n).

Terms

a(0) =0a(1) =1a(2) =1a(3) =3a(4) =3a(5) =11a(6) =9a(7) =35a(8) =33a(9) =105a(10) =105a(11) =339a(12) =313a(13) =1035a(14) =1017a(15) =3115a(16) =3099a(17) =9579a(18) =9345a(19) =28947a(20) =28713a(21) =86979a(22) =86825a(23) =263187a(24) =260865a(25) =791577a(26) =789497a(27) =2376555a(28) =2374521a(29) =7150443