a(1) = 0, a(2) = 1, and for n > 2, a(n) = 2*a(A252463(n)) + [n == 1 (mod 6)].

Terms

a(0) =0a(1) =1a(2) =2a(3) =2a(4) =4a(5) =4a(6) =9a(7) =4a(8) =4a(9) =8a(10) =18a(11) =8a(12) =37a(13) =18a(14) =8a(15) =8a(16) =74a(17) =8a(18) =149a(19) =16a(20) =16a(21) =36a(22) =298a(23) =16a(24) =9a(25) =74a(26) =8a(27) =36a(28) =596a(29) =16