Edit: Redacted: left for consistency. Had him confused there.

A closed form expression is basically just a mathematical function used to model a potentially infinite series.

Take a look here: http://en.wikipedia.org/wiki/Closed-form_expression

Look at the first and second examples.

You'll see the big summation sign (for loop: i to infinite) and then an explicit function.

If you want to think, what the heck is this math crap used for: think about a more basic everyday concept like recursion. How do you know it will terminate?

I don't think he is talking about the closed form expression (at least I know what a closed-form is and still couldn't understand the question).

There was no information whatsoever about what changes on each iteration... if nothing changes then the answer would be a constant of whatever rabbits were at the beginning... and that doesn't sound about right :/

Bah got ya.

Thank god I am not alone...

Good to hear. I'm working as a Jr. Software Engineer now, and I don't consider mathematics one of my strong points. Do many positions actually expect people to know these kinds of questions? I'd crash and burn here.