a(n) = floor(a(n-1)/2) if this is positive and not yet in the sequence, otherwise a(n) = 10*a(n-1).

Terms

a(0) =1a(1) =10a(2) =5a(3) =2a(4) =20a(5) =200a(6) =100a(7) =50a(8) =25a(9) =12a(10) =6a(11) =3a(12) =30a(13) =15a(14) =7a(15) =70a(16) =35a(17) =17a(18) =8a(19) =4a(20) =40a(21) =400a(22) =4000a(23) =2000a(24) =1000a(25) =500a(26) =250a(27) =125a(28) =62a(29) =31