chandra sekaran on Sat, 25 Jun 2016 05:51:45 +0200

 Need permutation help for n!/(n-r)!

• To: pari-users@pari.math.u-bordeaux.fr
• Subject: Need permutation help for n!/(n-r)!
• From: chandra sekaran <sekar.bc@gmail.com>
• Date: Sat, 25 Jun 2016 09:21:37 +0530
• Delivery-date: Sat, 25 Jun 2016 05:51:45 +0200
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numtoperm(n,k) will give  k-th permutation for n!.

Any function for n!/(n-r)! available?

For n!/(n-r)!, Let n = 50 and r = 3.
If we define r as subset say [2,3,5] i want
calculate the number where [2,3,5] occur and reverse also.

Any direct function available and if not how to calculate.

Thanks

Chandrasekaran B