How to determine how long a recursive fibonacci algorithm will take for larger values if I have the time for the smaller values?
<p>I have used the time library and timed how long the recursive algorithm takes to calculate the fib numbers up to 50. Give those number, is there a formula I can use to determine how long it would have potentially taken to calculate fib(100)?</p>

<p>Times for smaller values:</p>

<pre><code>Fib(40): 0.316 sec
Fib(80): 2.3 years
Fib(100): ??? 
</code></pre>