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Re: Combinations

  • To: mathgroup at smc.vnet.net
  • Subject: [mg30779] Re: [mg30769] Combinations
  • From: Andrzej Kozlowski <andrzej at tuins.ac.jp>
  • Date: Wed, 19 Sep 2001 00:16:19 -0400 (EDT)
  • Sender: owner-wri-mathgroup at wolfram.com

No, they are defintitely not present in the Mathematica Kernel. However, 
I think I am not the only one who is against the idea of littering the 
Kernel with such trivialities. I can't believe that you would fint it 
easier to write NumberOfPermutations[5] than 5! or 
NumberOfCombinations[7,5] than 7!/(5!2!).

On Monday, September 10, 2001, at 09:43  AM, Dana wrote:

> Hello.  I have Mathematica 4.1
>
> In a Program like Excel, or a hand-held calculator, one can return the
> number of combinations and permutations.
>
> However, I can not find an equivalent function in Mathematica.
> For example, Permutations[ ] returns a long list of all the "Actual"
> permutations.
> I am looking for just the final number.
> If there is one, could you include 'how' you found it.  I have looked
> everywhere.
> I know DiscreteMath`Combinatorica` has some stuff in it, but the Help 
> system
> appears not to explain many of them.
>
> I can write a custom function, but I am curious to find out if this 
> function
> is built in to Mathematica.
>
> I hope the answer is not to take the Length[ ]  of a rather long list.
>
> TIA.  Dana
>
> (I posted this question a month ago, but it never showed up in the
> newsgroup, or in the archives.
> I hope I am not doing something wrong.)
>
>
>
>
>
>

Andrzej Kozlowski
Toyama International University
JAPAN
http://platon.c.u-tokyo.ac.jp/andrzej/


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