### Problem 622

Posted:

**Thu Apr 12, 2018 7:54 pm**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?

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Posted: **Thu Apr 12, 2018 7:54 pm**

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?

Posted: **Thu Apr 12, 2018 8:01 pm**

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.Posted: **Thu Apr 12, 2018 8:05 pm**

Thanks

Posted: **Mon Jan 07, 2019 7:47 am**

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

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