Fibonacci series using php.....

This code generates the fibonacci series upto n numbers.

<?php
$a=0;
$b = 1;
$n =20;
print $a.'<br>';
for($i=1;$i<$n;$i++)
   {
   $final = $a + $b;
   $a = $b;
   $b = $c;
   if($c<n)
  {
         break;
  }
   print $c.'<br>';
   }
?>