I think it's:
Spoiler:
8,4,2,1 and from then on it's 2,1 for ever
if x/2 is an integer next number is x/2
if x/2 leaves a remainder, add result integer to remainder and all of it to x for next number.
It's late and I'm not sure I'm making sense, and I can't remember how to express this mathematically, so I analyse:
9/2=4, remainder 1. So next number is 9+4+1=14
14/2=7, so next number is 7
7/2=3, remainder 1. So next number is 7+3+1=11
....
5/2=2, remainder 1. So next number is 5+2+1=8
8/2=4, so next number is 4
4/2=2 so next number is 1
2/2=1,so next number is 1
1/2=0, remainder 1, so next number is 1+0+1=2, etc
(edit)
The way obs20 put it is so much simpler... Result is the same though.