No of processes
	P(0) = P(1) = 1
	P(n) = P(n-1) + P(n-2)

No of calls
	C(0) = C(1) = 1
	C(n) = 1 + C(n-1) + C(n-2)

No of leaves
	L(0) = L(1) = 1
	L(n) = L(n-1) + L(n-2) + P(n)
