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Permutations count (Posted on 2015-10-01)

Find the number of permutations of (1,2,3...n) possessing the following feature:

The number n is the only local maximum e.g. 123465, 123564, 654321,
as opposed to 651432, 261354.

See The Solution Submitted by Ady TZIDON

Rating: 3.0000 (1 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)

error in "official solution"

| Comment 9 of 10 |

Ady, shouldn't it say f(n+1) = 2*f(n) ?

Posted by Steve Herman on 2015-10-02 19:02:32

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