# R Programming : Find the Fibonacci Sequence

Tutorial by:Maria Ghoste      Date: 2016-06-10 02:36:23

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.

## Source Code

``````# Program to diplay the fibonacci
# sequence up to n-th tern where
# n is provided by the user

# 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 by adding the preceding two terms. We then interchange the variables (update it) and continue on with the process.

## R Programming

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