title: Convert a decimal into an alphabetic column id?
body: <p>Working with some spreadsheet stuff, internally the columns are referred to by a simple decimal number (0 indexed), but for the output, I need it to be in the standard human readable format:</p>
  
  <pre><code>A, B, C, .. Z, AA, AB, AC, .. AZ, BA ..
  </code></pre>
  
  <p>I first thought "easy! I'll just switch to base 26 and use [A-Z] instead of [0-9A-P]", except that using this technique makes A => 0. B => 1. Therefore the sequence actually goes like this:</p>
  
  <pre><code>A, B, .. Y, Z, BA, BB
  </code></pre>
  
  <p>How do you convert decimals to an excel-style column name?</p>