Not strange
The first to numbers are used for people from a special location. 84.XXX.XXX.XXX is for people in Germany and middle europe.
The next number indicates more accurate in which location you are.
The rest may change after every log-in or at least after 24h because the most providers log you automatically out then. This is because the IP pool is almost exhausted and they have to give the IP immediately to another one when you logged off.