a(0)=0, a(1)=a(2)=1; for n >= 1, a(3n+2) = 2a(n+1) + a(n), a(3n+1) = a(n+1) + 2a(n), a(3n) = 3a(n).

Terms

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