## Problem 622

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Oliver1978
Posts: 165
Joined: Sat Nov 22, 2014 9:13 pm
Location: Erfurt, Germany

### Problem 622

From what I gather from the problem description, the outcome of s(n) is 0 if n is odd, else some value > 0. Is this right?
49.157.5694.1125

hk
Posts: 10315
Joined: Sun Mar 26, 2006 9:34 am
Location: Haren, Netherlands

### Re: Problem 622

From the problem description:
Let $s(n)$ be the minimum number of consecutive riffle shuffles needed to restore a deck of size $n$ to its original configuration, where $n$ is a positive even number.
So if $n$ is odd $s(n)$ is not defined.

Oliver1978
Posts: 165
Joined: Sat Nov 22, 2014 9:13 pm
Location: Erfurt, Germany

### Re: Problem 622

Thanks
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Jochen_P
Posts: 50
Joined: Mon Oct 05, 2009 9:47 am
Location: Stuttgart, Germany

### Re: Problem 622

Really interesting little problem (imho 15% is a bit low)
In the mean time I know exactly what the maximum deck size for s(n) = 60 is, or any other amount of shuffles for that matter, (No, you can't shuffle this deck by hand or even forklift ) but the decks in between are still a mistery to me.

You really could've asked for s(n)=31