From: peter.luschny@gmail.com   
      
   Simple question: What is   
      
        sum_{i=0..n} binomial(n-i-1, n-i) ?   
      
   I compiled some answers:   
      
   ** Wolfram Alpha : 0   
      
   ** Maple : returns unevaluated   
      
   ** Sage 6.2 combined with mpmath really excels:   
   Depending on the order of the execution it gives   
   either a TypeError or the answer 1.0.   
      
   So, what is sum_{i=0..n} binomial(n-i-1, n-i) and why   
   can the writers of CASs not agree on the answer?   
      
   Here you can see the outputs:   
   http://luschny.de/temp/JoyOfCAS.png   
      
   Peter   
      
   --- SoupGate-Win32 v1.05   
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