Infinity is not a term for a sequence. It's a number.

I find it fascinating almost to watch people who don't know about a subject argue about it. Mathematics goes beyond what you've learned. Otherwise, they'd give you a doctoral degree in mathematics right now.

To set everyone straight:

Both positive and negative infinity exist, and there is a difference between the two.

In traditional mathematics, dividing a number by 0 isn't done. You can call it undefined if you want. If you wanted to be correct, however, you would say that it simply isn't done. If you had an actual application for it, you would use a limit of 0 instead of the actual number and reach infinity as an answer.

What is it they say about silence being golden?