"So you need a reference for 1 + 1?"
No, but then again, that's what calculators are for.
There's a difference between 1+1=2 and solving the recurrence relations
f(0)=0
f(n)=2f(floor(n/2))+n
The former does not require any sophistication beyond counting on your fingers. The recurrence, while being comparatively simple and essential to the study of computer science (show me a CS major who does not know what this might represent or how to solve it, and I'll show you a CS major who's not worth his salt), should come along with some sort of explanation or source. There are steps involved in finding a solution (unless you already know the solution).
