Binary expansion starts 111.

Terms

a(0) =7a(1) =14a(2) =15a(3) =28a(4) =29a(5) =30a(6) =31a(7) =56a(8) =57a(9) =58a(10) =59a(11) =60a(12) =61a(13) =62a(14) =63a(15) =112a(16) =113a(17) =114a(18) =115a(19) =116a(20) =117a(21) =118a(22) =119a(23) =120a(24) =121a(25) =122a(26) =123a(27) =124a(28) =125a(29) =126