[seqfan] Re: Non-collinear permutations

Ron Hardin rhhardin at att.net
Mon Jun 21 21:37:15 CEST 2010


Number of permutations of 1..n with no three points (i,p(i)) (j,p(j)) (k,p(k)) collinear.

Number of nXn permutation matrices with no three 1's collinear.

Better wording?  Specificity seems to introduce too much machinery.

E.g., 1,2,3  and 3,2,1 seem to cry out collinear on their own.

 rhhardin at mindspring.com
rhhardin at att.net (either)



----- Original Message ----
> From: "franktaw at netscape.net" <franktaw at netscape.net>
> To: seqfan at list.seqfan.eu
> Sent: Mon, June 21, 2010 1:48:11 PM
> Subject: [seqfan] Re: Non-collinear permutations
> 
> I assume that you mean that no three points of the form (n,p(n)) are 
> collinear. You should clarify this in a comment.

Franklin T. 
> Adams-Watters


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