In this article i will write a program to print Fibonacci numbers upto 20. This is very basic program we were writing in our college time. In Fibonacci number each number is sum of previous tow numbers. first tow numbers of Fibonacci number is 0 and 1, the next number will be (0+1) = 1, next will be (1+1) = 2, next will be (1+2) = 3 and so on.

Here is the code for Fibonacci numbers.

Here is the Output :

Here is the code for Fibonacci numbers.

`<?php`

$limit = 20;

echo $first = 0;echo '<br/>';

$second = 1;

while($limit > 0){

echo $next = $first + $second;echo '<br/>';

$second = $first;

$first = $next;

$limit--;

}

?>

0

1

1

2

3

5

8

13

21

34

55

89

144

233

377

610

987

1597

2584

4181

6765

1

1

2

3

5

8

13

21

34

55

89

144

233

377

610

987

1597

2584

4181

6765