Take alternate digits of 2^n.

Terms

a(0) =1a(1) =2a(2) =4a(3) =8a(4) =1a(5) =3a(6) =6a(7) =18a(8) =26a(9) =52a(10) =12a(11) =24a(12) =49a(13) =89a(14) =134a(15) =378a(16) =656a(17) =117a(18) =224a(19) =548a(20) =1456a(21) =2912a(22) =4934a(23) =8868a(24) =1771a(25) =3543a(26) =6186a(27) =14178a(28) =28346a(29) =56792