While the circumstance of him going out with others does strongly suggest what you are thinking (that he does not like you), I would probably not go so far to assume that as a fact. It does look like he prefers to spend his spare time with his other friends. There may be a number of reasons for that: It is more relaxing for him to spend his time in a group, he likes them more, he needs some time off from you or a number of other reasons one of them being, he does not like you.
What I find more relevant is the fact, that he only comes to you when he needs something. That is not a good basis for friendship.
I would also look for other clues, like how does he talk to me, what is the facial expression when he sees me, does he seem to enjoy himself in my presence. But, some people are just too polite so you cannot know for certain.
From what you wrote, I would probably not pursue this "friendship", unless the other person shows some genuine interest.
With a good friend, it should be possible to just ask what's going on (but that also depends on a number of things: the duration of the friendship, how comfortable you both are with being honest, the cultural setting) ...
Disclaimer: I am new in this community. This is my personal opinion based on my personal observations and experience.