Entirely correct. The purpose of a phone screen is to rule out the cases where a candidate will come in, be scheduled for 6-8 hours of interviews and receive a

Entirely correct. The purpose of a phone screen is to rule out the cases where a candidate will come in, be scheduled for 6-8 hours of interviews and receive a "no" from every interviewer. Recursive Fibonacci numbers are also a good way to work Memoization into the picture.