title: need algorithm to find the nth palindromic number
body: <p>consider that</p>
  
  <pre><code>    0 -- is the first
      1 -- is the second
      2 -- is the third
      .....
      9 -- is the 10th
      11 -- is the 11th
  </code></pre>
  
  <p>what is an efficient algorithm to find the nth palindromic number?</p>