A081254-A072762.

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =0a(7) =1a(8) =2a(9) =4a(10) =8a(11) =16a(12) =32a(13) =65a(14) =130a(15) =260a(16) =520a(17) =1040a(18) =2080a(19) =4161a(20) =8322a(21) =16644a(22) =33288a(23) =66577a(24) =133154a(25) =266309a(26) =532618a(27) =1065236a(28) =2130472a(29) =4260944