Trajectory of 3 under map n->13n+1 if n odd, n->n/2 if n even.

Terms

a(0) =3a(1) =40a(2) =20a(3) =10a(4) =5a(5) =66a(6) =33a(7) =430a(8) =215a(9) =2796a(10) =1398a(11) =699a(12) =9088a(13) =4544a(14) =2272a(15) =1136a(16) =568a(17) =284a(18) =142a(19) =71a(20) =924a(21) =462a(22) =231a(23) =3004a(24) =1502a(25) =751a(26) =9764a(27) =4882a(28) =2441a(29) =31734