<!-- To generate a png from this file, I used mathmlsvg and the gimp (or inkscape)
      which came as standard with my Fedora 7 distribution at least. -->
<math xmlns="http://www.w3.org/1998/Math/MathML">
<mrow>
  <mstyle displaystyle='true'>
    <munderover>
      <mo>∑</mo>
      <mrow>
        <mi>n</mi>
        <mo>=</mo>
        <mn>1</mn>
      </mrow>
      <mn>∞</mn>
    </munderover>
    <mfrac>
      <mn>1</mn>
      <msup>
        <mn>2</mn>
        <mi>n</mi>
      </msup>
    </mfrac>
    <mo>=</mo>
    <mn>1</mn>
  </mstyle>
</mrow>
</math>

