Some verbs are commonly used in the -て + いる form. For example, "住んでいる" or "知っている". Do dictionaries typically indicate that they're used that way?
Not ever in my experience. ～ている is actually a grammar point, which explains why it wouldn't be in a dictionary for looking up vocabulary words. Yeah, the chances of you using 知る or 住む are rare, but the dictionary assumes you just want to know the word and already know how to use it. Often, this isn't the case, but that's why you study outside of dictionaries, haha.
I hope this makes sense... I have a habit of misunderstanding questions.