title: How to find all instances of mirrored duplicates?
body: <p>I have been searching for some time now for any answers on how to do this.</p>
  
  <p>What I am trying to do is, take an array of numbers, e.g. <code>{1, 3, 5, 6, 8, 7, 6 ,5, 3, 1}</code> (but it will use user input) and find the duplicates of these numbers that are mirrored and return how many indexes are involved in just one instance of said array.</p>
  
  <p>I know the basics of C# but can't grasp this task. No, this is not homework. This is my own project to further my knowledge.</p>
  
  <p>I am not currently around the code I have for parts of this, but would really appreciate any help/advice anyone could give me.</p>