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Factorials and 2 powers (Posted on 2021-08-13) Difficulty: 3 of 5
Find all pairs (k,n) of positive integers such that

k!=(2n-1)(2n-2)(2n-4)...(2n-2n-1)

No Solution Yet Submitted by Danish Ahmed Khan    
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re(2): Poor attempt at an explanation | Comment 4 of 5 |
(In reply to re: Poor attempt at an explanation by broll)

No, see my example again.  You aren't considering k and n can be different numbers.   For other pairs (k,n) each side can have the same number of factor of two.


The next example is (68,11) both have 66 factors of 2.
By this time the factors of 3 have widely diverged at 31 and 6 respectively.




  Posted by Jer on 2021-08-15 13:25:09
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