Support combinatorics?
After proper transformations you can calculate at least simple combinations and permutations in Spotlight:

7P4=7!/(7-4)!=7!/3!. Entered in Spotlight as 7!/3! it will give you a proper result: 840.

C(8,5)=8!/5!(8-5)!=8!/5!3!. Entered in Spotlight as 8!/5!3! it will give you a proper result: 56.

For info on other advanced functions besides Factorial which Spotlight can handle, see this page



According to Google Search a WolframAlpha Spotlight plug-in for Flashlight (a Spotlight extender - link in the other answer) which should be capable of doing these kind of calculations once existed but I can't actually find it or it's gone.



With Google Chrome installed you can use a work-around and add the Wolfram | Alpha extension which supports expressions like in your question in the extra search bar: