# R Program to Print the Fibonacci Sequence

In this example, you’ll learn to print the Fibonacci sequence using a while loop.

To understand this example, you should have the knowledge of following R programming topics:

A Fibonacci sequence is the integer sequence of

0, 1, 1, 2, 3, 5, 8....

The first two terms are 0 and 1. All other terms are obtained by adding the preceding two terms.

This means to say the nth term is the sum of (n-1)^{th} and (n-2)^{th} term.

You can also print the Fibonacci sequence using a recursive function. Learn more about how to print the Fibonacci sequence using recursion.

## Example: Print Fibonacci Sequence

```
# take input from the user
nterms = as.integer(readline(prompt="How many terms? "))
# first two terms
n1 = 0
n2 = 1
count = 2
# check if the number of terms is valid
if(nterms <= 0) {
print("Plese enter a positive integer")
} else {
if(nterms == 1) {
print("Fibonacci sequence:")
print(n1)
} else {
print("Fibonacci sequence:")
print(n1)
print(n2)
while(count < nterms) {
nth = n1 + n2
print(nth)
# update values
n1 = n2
n2 = nth
count = count + 1
}
}
}
```

**Output**

How many terms? 7 [1] "Fibonacci sequence:" [1] 0 [1] 1 [1] 1 [1] 2 [1] 3 [1] 5 [1] 8

Here, we ask the user for the number of terms in the sequence. We initialize the first term to 0 and the seconde term to 1.

If the number of terms is more than 2, we use a `while`

loop to find the next term in the sequence.

Inside the while loop, we first print the first two terms `n1` and `n2` respectively. Then, we calculate the next term `nth` by adding the last two terms and print it.

Now, we update the values of `n1` and `n2` to the last two terms, i.e. the term in `n2` to `n1` and the term we just calculated `nth` to `n2`.

This goes on until the number of terms reaches the `nterms` entered by the user.