title: n^(-1/3) vs (n!) ^ 2 vs 2 ^ (n^2). Factorial square or exponential with index( n^2)?
body: <p>Which is a better function complexity wise: <code>n^(-1/3)</code> vs <code>(n!) ^ 2</code> vs <code>2 ^ (n^2)</code>?</p>
  
  <p>Sterling's approximation would give <code>n! -&gt; nlogn</code> so would it get converted into <code>n^2 (log n)^2</code>.</p>