Voce pode fazer assim: $fixos = "1,5,12,14,23,32,34,41,45,6,10,17,19,28,37,39,46,50,51,55,62,64,73,82,84,91,95,56,60,67,69,78,87,89,96,00";
$nao_fixos = "2,3,4,7,8,9,11,13,15,16,18,20,21,22,24,25,26,27,29,30,31,33,35,36,38,40,42,43,44,47,48,49,52,53,54,57,58,59,61,63,65,66,68,70,71,72,74,75,76,77,79,80,81,83,85,86,88,90,92,93,94,97,98,99";
function random_char($string)
{
$length = strlen($string);
$position = mt_rand(0, $length - 1);
return($string[$position]);
}
function random_string ($charset_string, $length)
{
$return_string = random_char($charset_string);
for ($x = 1; $x < $length; $x++)
$return_string .= random_char($charset_string);
return($return_string);
}
$resultado = $fixos + random_string($nao_fixos, 14);
echo $resultado; não testei mas ve se funciona