$code = $_POST['code'];
  $cant = intval($_POST['cant']);
  $nums = preg_split('/[^0-9]+/i', $code);
  $strings = preg_split('/[^a-zA-Z]+/i', $code);
  $intN = $nums[1];

 for($i = 0; $i < $cant; $i++){
    echo json_encode($intN++);
  }

echo json_encode(str_pad($intN++, 10, "0", STR_PAD_LEFT));