Numbers that reach ...,7,8,4,2,1 under the mapping: if n is even divide by 2 else add 1.

Terms

a(0) =13a(1) =14a(2) =25a(3) =26a(4) =27a(5) =28a(6) =49a(7) =50a(8) =51a(9) =52a(10) =53a(11) =54a(12) =55a(13) =56a(14) =97a(15) =98a(16) =99a(17) =100a(18) =101a(19) =102a(20) =103a(21) =104a(22) =105a(23) =106a(24) =107a(25) =108a(26) =109a(27) =110a(28) =111a(29) =112