ch transcendent function.
        </li>
        <li>
          <b>LOCK</b> returns the number of codes for a lock with N buttons.
        </li>
        <li>
          <b>MEIXNER</b> evaluates Meixner polynomials at a point.
        </li>
        <li>
          <b>MERTENS</b> evaluates the Mertens function.
        </li>
        <li>
          <b>MERTENS_VALUES</b> returns some values of the Mertens function.
        </li>
        <li>
          <b>MOEBIUS</b> returns the value of MU(N), the Moebius function