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Factorials and Powers (Posted on 2009-04-22) Difficulty: 3 of 5
Determine all possible pair(s) (X, Y), with X being a prime and Y being a positive integer, that satisfy this equation:

(X-1)! + 1 = XY

No Solution Yet Submitted by K Sengupta    
Rating: 4.0000 (2 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)
Thanks for your post, Harry | Comment 7 of 8 |
(In reply to Very little progress to report by Harry)

I had got as far as the equation in your fourth graf, and no farther, but your reference to Hardy sent me looking around.

I found this mathworld link http://mathworld.wolfram.com/WilsonPrime.html which mentions that the search has been extended to  <IMG class=inlineformula height=17 alt=510^8 src="http://mathworld.wolfram.com/images/equations/WilsonPrime/Inline2.gif" width=40 border=0> with no other solutions found.  That's enough for me. 

 


  Posted by xdog on 2009-04-24 17:52:57
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