title: Shell Sort Minimum Comparisons
body: <p>What is the minimum number of comparisons needed by shell sort to sort a list of 8 items, given a gap list of <code>5,1</code>?</p>
  
  <p>I understand that the best case performance is an <code>n(log(n))</code> case, but I can't work through the maths to get the full expression needed to put the given numbers in to get the minimum number of comparisons.</p>