Fibonacci In PHP

<?php

$first = 0;
$second = 1;
$current = 1;
$tableau = [];

$nbToFound = 51;

for ($i = 0; $i <= $nbToFound; $i++) {
    $tableau[] = $current;
    $current = $first + $second;
    $first = $second;
    $second = $current;
}

var_dump($tableau[$nbToFound]);