[seqfan] Re: Permutations with 2K-2 odd displacements, formula?
rhhardin at att.net
Sun Jun 2 14:13:35 CEST 2013
Trying proof again (the first k-1 evens don't have to go to the first k-1 odds
but can go to any odd)
Order the even elements (factorial((n+1)/2))
Order the odd elements (factorial(n/2))
The first k-1 even elements go somewhere in the odd elements (binomial(n/2,k-1))
The first k-1 odd elements go somewhere in the even elements
The even and odd elements after k-1 fill the empty even and odd slots
respectively in the chosen order
Waiting five minutes this time. Still seems okay.
rhhardin at mindspring.com
rhhardin at att.net (either)
----- Original Message ----
> From: Ron Hardin <rhhardin at att.net>
> To: Sequence Fanatics Discussion list <seqfan at list.seqfan.eu>
> Sent: Sun, June 2, 2013 7:16:30 AM
> Subject: [seqfan] Re: Permutations with 2K-2 odd displacements, formula?
> Sorry, the proof is nonsense. Something like the proof is right.
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