Trajectory of 1 under map n->39n+1 if n odd, n->n/2 if n even.

Terms

a(0) =1a(1) =40a(2) =20a(3) =10a(4) =5a(5) =196a(6) =98a(7) =49a(8) =1912a(9) =956a(10) =478a(11) =239a(12) =9322a(13) =4661a(14) =181780a(15) =90890a(16) =45445a(17) =1772356a(18) =886178a(19) =443089a(20) =17280472a(21) =8640236a(22) =4320118a(23) =2160059a(24) =84242302a(25) =42121151a(26) =1642724890a(27) =821362445a(28) =32033135356