What kind of math? Just curious.
Literally this:
http://upload.wikimedia.org/math/7/6/f/76f99713cf111eb035d90...
What's being implemented is pretty simple to write with an English explanation. But my interviewer expected me to get it from the notation above.
It's been a decade since I left high school, and the programming in my career doesn't involve formulae. After a bunch of successful interviews I bombed on this question, and was never forgiven.
That's the Fibonacci Series. It would be hard for me to forgive anyone who wouldn't at least recognize it too, since it is so famous and is basically the classic example of recursion.
EDIT: seeing as this thread is about a CS major trying to get a job, this is also something that is taught quite early in a CS curriculum ;)
The job was as a system administrator, emphasizing troubleshooting and automation. The question wasn't job related.
I can handle Fibonacci when the problem is described, but a page of math means nothing to me.
Worked out better in the long run.