Why Does OS X Mavericks Start Indexing After A Crash?
While reading up on this, I found two prevalent suggestions. One from this Ask Different thread:


  Try to erase the Spotlight index by either running sudo mdutil -Ea or by temporarily adding your startup disk to the privacy tab in the Spotlight preference pane.
  
  If that doesn't work, try to run:
  
  sudo lsof|grep mdworker
  
  or
  
  sudo mdutil -Ea;opensnoop -n mdworker
  
  to see if the indexing hangs on some specific files.


And the second, which I actually feel is more relevant to your case since your machine does finish indexing, suggested this:


  After trying everything under the sun, here's what fixed it for me
  
  Booted in Safe Mode and ran the free utility OnyX. 
  
  Cleaned system caches, repaired/restored permissions.