The above is completely correct, but I think there's more depth to the relationship as well. For instance, Huck does eventually run away from him, likely due to the beatings and other associated mistreatment...but there is an element of Huck that enjoys being in the woods with his father, so he doesn't have to be "sivilized" all the time.
It's kind of a relationship out of necessity; Huck may hate the way he is treated, and eventually fakes his own death to get away. This is not to mention that his father is ultimately killed for real, so we know he's a terrible person. There is, though, something about the escape from society that his father provides, and it seems like Huck wishes his father would be a decent human being.
Sadly, Huck and Pap have very little in the way of feelings for one another. Huck has a mixture of fear and hate towards his father. Pap feels like Huck is his property, but he feels very little love for him. He feels entitled to mistreat him, and doesn't miss him after Huck leaves, until it comes to his attention that Huck has come into quite a bit of money.
In the novel, The Adventures of Huckleberry Finn, a dynamic of Huck and Pap’s relationship is unconventionality. His father was never really there for him so he was never very close to him or really cared for him. “Pap he hadn't been seen for more than a year, and that was comfortable for me; I didn't want to see him no more”(Twain 3). They never had the traditional father and son relationship so they never seemed to care for one another. Their relationship was also unconventional because each of them cared only for themselves and not for one another. Usually in a family, the member care for one another and help each other. Pap only came back because he had heard of the money Huck had. He did not actually care to be by his son’s side, he only wanted the money. Their relationship is also very unloving because they do not show affection, which is unconventional. Pap is very abusive toward Huck when that is not a usual father and son dynamic. Pap harasses Huck and beats him which worsens their relationship even further.