# Fibonacci Series Program in C

## Write a C Program to find Fibonacci series up to n

The sequence is a Fibonacci series in C where the next number is the sum of the previous two numbers. The first two terms of the Fibonacci sequence is started from 0, 1.  ## Method 1

Write a program to print Fibonacci series method 1 below –

Run
```#include<stdio.h>

int main()
{
int n = 10;
int a = 0, b = 1;

// printing the 0th and 1st term
printf("%d, %d",a,b);

int nextTerm;

// printing the rest of the terms here
for(int i = 2; i < n; i++){
nextTerm = a + b;
a = b;
b = nextTerm;

printf("%d, ",nextTerm);
}

return 0;
}
```

### Output

`0, 1, 1, 2, 3, 5, 8, 13, 21, 34, `

## Method 2 (Recursion/static variable)

This method uses recursion in C, also uses static variables in C

Run
```#include<stdio.h>

int printFib(int n){

static int a = 0, b = 1, nextTerm;
if(n > 0)
{
nextTerm = a + b;
a = b;
b = nextTerm;

printf("%d, ",nextTerm);
printFib(n-1);
}

}

int main()
{
int n = 10;

printf("0, 1, ");

// n-2 as 2 terms already printed
printFib(n-2);

return 0;
}
```

### Output

`0, 1, 1, 2, 3, 5, 8, 13, 21, 34, `

## Method 3 (Recursion)

This method uses recursion in C, rather than static variables, we use pure recursion here. Run

```#include<stdio.h>

int getFib(int n){

if(n <= 1)
return n;

return getFib(n-1) + getFib(n-2);

}

int main()
{
int n = 10;

for(int i = 0; i < n; i++)
printf("%d, ",getFib(i));

return 0;
}
```

### Output

`0, 1, 1, 2, 3, 5, 8, 13, 21, 34, `

## Method 4 (Direct Formula)

We can use direct formula to find nth term of Fibonacci Series as –

Fn = {[(√5 + 1)/2] ^ n} / √5

Run

```#include<stdio.h>
#include<math.h>

int getFibo(double phi, int n) {

for(int i = 0; i <= n; i++)
{
// setting .0 precision so all leading decimals are not printed
// else would have printed 1.000000, 1.000000, 2.000000 so on....
printf("%.0lf, ",round(pow(phi, i) / sqrt(5)));
}
}

int main ()
{
int n = 15;
double phi = (1 + sqrt(5)) / 2;
getFibo(phi, n);

return 0;
}
```

### Output

`0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, `

### In other Languages –

Fibonacci Series upto nth term : C | C++ | Java | Python

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### One comment on “Fibonacci Series Program in C”

• diyaray.2002

#include
int main(){
int n,i,a=0,b=1,c;
printf(“Enter a number: “);
scanf(“%d”,&n);
if(n<0){
printf("Number of terms should be always greater than 0\n");
}
else{
for(i=1;i<=n;i++){
printf("%d ",a);
c=a+b;
a=b;
b=c;
}
}
} 0