Fibonacci numbers are a sequence of numbers
that are made by taking 0 and 1, and adding
them together to get 1, so you have 0, 1, and 1.
Then,take the 1 and 1, and add them together
to get 2, so you now have 0, 1, 1, and 2. Next
add the 2 and 1 to get 3, giving you
0, 1, 1, 2, and 3.

Using concise mathematical notation, if $F_n$ is the $n^{th}$ Fibonacci number, given that $F_0=0$ and $F_1=1$, then $F_n=F_{n-1}+F_{n-2}$.

This sequence is a good lesson-base for writing a function, so let's do that here.

Let's write a function that will
print the sequence of Fibonacci numbers. We'll call the
function `fib(n)`

, where `n`

is a number we pass the
function, telling it how many Fibonacci numbers we want it
to print. So we'd call it by programming `fib(10)`

to see the first
10 Fibonacci numbers (past the initial 0 and 1, etc.).

`first =`

, `second =`

and `next =`

lines according to the description of the
Fibonacci sequence described above.
Type your code here:

See your results here:

This code will not run! Given that the first two Fibonacci numbers are 0 and 1, what do you
think you should put in the

`first =`

and `second =`

lines? After this, the next
Fibonacci number is 3, which is the sum of `first`

and `second`

. So, what should you put
in for the `next =`

line?
Your code is working with it displays this sequence of numbers: 0, 1, 2, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144 ...

Not the logic: the old second number becomes the new first number. And the current number becomes the new second number, so the next time through the loop, the next number can be found buy adding the first and second once again. Dismiss.

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