title: How to write summation expression in HTML?
body: <p>How to write equivalent HTML expression for following Latex:  </p>
  
  <pre><code>$$\sum_{k=1}^Nk(N-k+1)  
  </code></pre>
  
  <p>The image is: </p>
  
  <p><img src="https://i.stack.imgur.com/MccTc.png" alt="enter image description here">    </p>
  
  <p>I did like this: </p>
  
  <pre><code>∑ &lt;sub&gt;k=1&lt;/sub&gt; &lt;sup&gt;N&lt;/sup&gt;  
  </code></pre>
  
  <p>but output is like this   </p>
  
  <p>∑ <sub>k=1</sub> <sup>N</sup>  </p>
  
  <p>I am not good at HTML and I searched on web but couldn't find answer. 
  Please help on this..Thanks!</p>