Trajectory of 1 under map n->21n+1 if n odd, n->n/2 if n even.

Terms

a(0) =1a(1) =22a(2) =11a(3) =232a(4) =116a(5) =58a(6) =29a(7) =610a(8) =305a(9) =6406a(10) =3203a(11) =67264a(12) =33632a(13) =16816a(14) =8408a(15) =4204a(16) =2102a(17) =1051a(18) =22072a(19) =11036a(20) =5518a(21) =2759a(22) =57940a(23) =28970a(24) =14485a(25) =304186a(26) =152093a(27) =3193954a(28) =1596977a(29) =33536518