I need to find f24. I know F23=28657 and f25=75025. I have figured out that F24 is 46368 using F(n)=F(n-1)+F(n-2).

Question

My problme is asking me for two values of n for which Fn=n. I do not understand what it is asking.

Answer 1

As you said, f23=28657, but 23≠28657.
You need to find 2 values of n where fn=n.

f0=0 is one example. There are two more, and they are at the beginning of the sequence, so you must have gone past them a few times already.

Answer 2

There is only one Fn = n and that's n=1

Answer 3

Bzzt! Just start a list

n = 1 2 3 4 5 6
Fn = 1 1 2 3 5 8

F1 = 1
F5 = 5

Answer 4

Using the golden ratio, what if f24,f27,f29,f31,f34,f38,f40,f45,f48,f70?