Online PHP editor | refs for U7UXd

@ 2014-09-16T09:59:21Z

<?php
$chars = array(0,1,2,3,4,5,6,7,8,9);
$serial = '';
$max = count($chars)-1;
for($j=0;$j<20;$j++){
for($i=0;$i<20;$i++){
    $serial .= (!($i % 3) && $i ? '-' : '').$chars[rand(0, $max)];
}
echo $serial.PHP_EOL;
$serial = '';
}