Well i'm not so good at math, but i have the following task: Here's the code:
int foo(n): if n <= 0: return 1 else: return foo(n-1)+foo(n-3)-1
What's foo(7) will return?
So i have to answer without using any devices. And thoughts about drawing trees by hand puzzles me. Is there any way to represent such function into simple math formula without deep math =) And what's the formula for this function.