title: While Trying to def: TypeError: unsupported operand type(s) for ** or pow(): 'NoneType' and 'int'
body: <p>I was using this code in Python 2.7 to produce a new number by:</p>
  
  <pre><code>def Alg(n):
      n=((n**2)-1)/4
      return n    
  </code></pre>
  
  <p>and I get the error message:</p>
  
  <pre><code>TypeError: unsupported operand type(s) for ** or pow(): 'NoneType' and 'int'
  </code></pre>
  
  <p>Any help would be great! Thanks!</p>