If you take the characters a-z and the numbers 1-9, you have 35 characters,
yes. When you use them in a sequence of up to 3 characters, you have:

   - 35 + 35^2 + 35^3 = 44,135 sequences

Then, if you take three of those sequences, and allow repeats, you have

   - 44,135^3 =   85970488160375 possible triplets

If you don't allow repeats, you have:

   - 44,135 * 44,134 * 44,133 = 85964644553970 possible triplets.

At least, that's what I get, using my admittedly rusty knowledge of
combinatorics.

Thanks,
Rohit Patnaik

On Sun, Oct 14, 2012 at 5:19 PM, Kevin LaTona <[email protected]> wrote:

> I am working on a weekend project idea and was wondering if anyone on the
> list could verify a math problem for me?
>
>
>
> Here is the problem.
>
> If one takes the characters a-z and  numbers 1-9 this gives one 35
> possible character options.
>
> Now if used in a sequence of up to 3 characters.
>
> I get a total of 6,545 possible combinations of these 35 characters.
>
>
>
> Now if one was to use them in file folder tree style structure such as,
>
> ad6 / 7gh / d8s
>
> My math shows there is 46,706,638,440 possible combinations of these 35
> characters in a 3 layer deep tree.
>
> Do you get the same results or am I doing something wrong here?
>
> Thanks your thoughts on the matter.
> -Kevin
>
>
>
>
> This is the rather quick and dirty Python code I used to get to these
> results today.
>
> import math
>
> a = math.factorial(35)
> b = math.factorial(35-3)
> c = math.factorial(3)
> d = a / (b*c)
> '{:,}'.format(d)
> #'6,545'
>
>
> e = math.factorial(6545)
> f = math.factorial(6545-3)
> g = math.factorial(3)
> h = e / (f*g)
> '{:,}'.format(h)
> #'46,706,638,440'
>

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