recursive power algorithm Have a look at my (javascript) version of a O(log(n)) xn algorithm:

function pow(x,n)
{
     return n==0?1:n==1?x:n==2?x*x:pow(pow(x,(n-n%2)/2),2)*(n%2==0?1:x);
}


Can you get it shorter?
BrainFuck (482 characters)

Solution is modulo 256. Reads n in digit by digit.  Each time it sees a new digit d, it raises the current value to the tenth power and then multiplies that by x^d
Input must be x followed by single space, followed by n, followed by newline

&gt;,--------------------------------[---------------&gt;,--------------------------------]&lt;[&lt;]&gt;&gt;[&lt;-[-&gt;++++++++++&lt;]&gt;&gt;]&lt;-&gt;+&gt;&gt;&gt;&gt;&gt;,----------[--------------------------------------&lt;++++++++++&lt;+&gt;[-&lt;[-&lt;&lt;&lt;[-&gt;+&gt;+&lt;&lt;]&gt;[-&lt;+&gt;]&gt;&gt;]&lt;[-&gt;+&lt;]&gt;&gt;]&lt;[-&lt;+&gt;]&gt;&gt;[-&lt;&lt;+&gt;&gt;]&lt;&lt;&lt;&lt;&lt;[-]&gt;&gt;&gt;[-&lt;[-&lt;&lt;&lt;[-&gt;+&gt;+&lt;&lt;]&gt;[-&lt;+&gt;]&gt;&gt;]&lt;[-&gt;+&lt;]&gt;&gt;]&lt;[-&lt;&lt;+&gt;&gt;]&gt;&gt;&gt;,----------]&gt;&gt;+&lt;&lt;+&lt;&lt;+&lt;&lt;+&lt;&lt;[-]&gt;[-&gt;[&gt;+----------[&gt;-&lt;[-&lt;+&gt;]]&lt;-[-&gt;+&lt;]+&gt;++++++++++&gt;]+&lt;&lt;[&lt;----------&lt;]&gt;++++++++++]&gt;[&gt;++++++++++++++++++++++++++++++++++++++++++++++++&gt;]&lt;&lt;&lt;&lt;[&gt;.&lt;&lt;&lt;]++++++++++.