2 things:
If you stick with the original form of your answer (a recurrance-based one), try Memoizing it, viz.: 
# Compute Fibonacci numbers, straight from Memoize docs
use Memoize;
memoize('fib');

sub fib {
     my $n = shift;
     return $n if $n < 2;
     fib($n-1) + fib($n-2);
}

my $foo = fib(24);

[download]
Such a strategy stores the results of previous iterations for later use, so you only have to calculate each result once. Once you do, it's stored (behind the scenes) in a hash which reconstructs it on demand. This makes things much faster.

But more importantly, I would offer this verson of an answer as a possible contender. It's a one-liner, but of a different style: 
sub fib{int(((((1+sqrt(5))/2)**$_[0])/sqrt(5))+.5)}

[download]
enjoy!



Code is (almost) always untested.
http://www.justicepoetic.net/

In reply to Re: Fibonacci Numbers by jweed
in thread Fibonacci Numbers by dReKurCe

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