Permutations with fixed points
Martin Fuller
martin_n_fuller at btinternet.com
Fri Jan 4 22:01:39 CET 2008
A000166 (permutations with no fixed points) contains the following
formula: "The termwise sum of this sequence and A003048 gives the
factorial numbers". A003048 has an equivalent formula.
I do not understand how that formula works. Should it refer to A002467
instead?
Martin Fuller
--- Tanya Khovanova <mathoflove-seqfan at yahoo.com> wrote:
> Your sequence is the sequence A002467 minus one, as you do not count
> an
> identical permutation.
>
> Tanya
>
> --- zak seidov <zakseidov at yahoo.com> wrote:
>
> > Dear seqfans,
> > what is wrong with this sequence?
> > why is not it in OEIS?
> > thanks, zak
> >
> > 0,3,14,75,454,3185,25485,229382
> > Number of permutations of set {1..n} with at least one
> > fixed point, n>=2.
> > a(3)=3 because there are three permutations with at
> > least one fixed point
> > with {1,2,3}:
> > {1,3,2},{2,1,3},{3,1,2};
> > a(4)=14 because there are 14 permutations with at
> > least one fixed point
> > with {1,2,3,4}:
> >
>
{1,2,4,3},{1,3,2,4},{1,3,4,2},{1,4,2,3},{1,4,3,2},{2,1,3,4},{2,3,1,4},{2,4,3,1},{3,1,2,4},{3,2,1,4},{3,2,4,1},{4,1,3,2},{4,2,1,3},{4,2,3,1}
> >
> >
> > --- superseq-reply at research.att.com wrote:
> >
> > > Date: Fri, 4 Jan 2008 10:53:31 -0500 (EST)
> > > From: superseq-reply at research.att.com
> > > To: zakseidov at yahoo.com
> > > Subject: Reply from superseeker
> > >
> > > Report on [ 14,75,454,3185,25485,229382]:
> > > Many tests are carried out, but only potentially
> > > useful information
> > > (if any) is reported here.
> > >
> > >
> > > Even though there are a large number of sequences in
> > > the table, at least
> > > one of yours is not there! Please send it to me
> > > using
> > > the submission form on the sequence web page
> > >
> > http://www.research.att.com/~njas/sequences/Submit.html
> > > and I will (probably) add it! Include a brief
> > > description. Thanks!
> > >
> > > o Take a look at my web page which does lookups
> > > "online"! Go to:
> > > http://www.research.att.com/~njas/sequences/
> > > o The whole sequence table is also visible there,
> > > as well as
> > > an explanation of the symbols used in the
> > > table.
> > > o If the sequence you looked up was not in the
> > > table,
> > > please send it to me using the submission form
> > > on the web page!
> > > o The server sequences at research.att.com does a
> > > simple lookup in the
> > > On-Line Encyclopedia of Integer Sequences
> > > o If the word "lookup" does not appear you will be
> > > sent the help file.
> > >
> > > Sequentially yours, The On-Line Encyclopedia of
> > > Integer Sequences,
> > > N. J. A. Sloane, AT&T Research, Florham Park NJ
> > > 07932-0971 USA njas at research.att.com
> > >
> >
> >
> >
> >
> >
>
____________________________________________________________________________________
> > Never miss a thing. Make Yahoo your home page.
> > http://www.yahoo.com/r/hs
> >
>
>
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