From: "Eric I." <rubytraining@...>
Date: 2008-06-09T03:13:46+09:00
Subject: Re: Preferable Pairs (#165)

On Jun 7, 11:05 pm, "Eric I." <rubytrain...@gmail.com> wrote:
> By the way, if there are n people, I believe the formula for the
> number of partnership schemes is:
>
>     n! / (n / 2)! / 2**(n / 2)

An alternative (and more efficient) way to compute the number of
partnership schemes is to multiply all the odd values from 1..n.  For
example, if there are eight people, then we have 1 * 3 * 5 * 7, or
105.

Eric

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