[seqfan] Re: Claude Lenormand and raboter(n)
njasloane at gmail.com
Mon Sep 10 06:07:42 CEST 2018
Dear Seq Fans,
Concerning the paper by Claude Lenormand which I mentioned earlier:
I scanned it and added it to several sequences that it mentions.
In my earlier message I mentioned his SECOND procedure, that he calls
the "raboter" transform,
and for which I created A318921. (You can see his paper there)
His FIRST procedure simply looks at the lengths of the successive runs
in a word,
what I call the RUNS transform.
I started to go though his paper in detail, adding several new
sequences to the OEIS, and adding references from sequences that were
already in the OEIS.
A318928, A318929 and A318930 are new.
I ran out of time on page 2: I stopped at the line "Pour la suite s
engendre'e par la programme "
If anyone would like to help by continuing from this point (adding
references if a sequence is in the OEIS, or adding
sequences to the OEIS if they are new), please do so. I just don't
have time to work any more on this paper.
It is a very interesting paper, so I hope someone will take over the job.
Neil J. A. Sloane, President, OEIS Foundation.
11 South Adelaide Avenue, Highland Park, NJ 08904, USA.
Also Visiting Scientist, Math. Dept., Rutgers University, Piscataway, NJ.
Phone: 732 828 6098; home page: http://NeilSloane.com
Email: njasloane at gmail.com
On Sun, Sep 9, 2018 at 1:25 AM, Neil Sloane <njasloane at gmail.com> wrote:
> So A175046 is a kind of inverse transformation to A318921! Thanks,
> Andrew, very nice!
> I've created A318922, ...923, ...924 applying the A318921
> transformation to Fibonaccis, primes, binary Campernowne,
> It might be interesting to see what A175046 does to those same three
> sequences, if anyone would like to investigate.
> Inspired by your email, I also created the companion A318925, defined
> by a(n) = A175046(A318921(n)). (Needs more terms)
> Since Claude Lenormand used <<raboter>> to describe what is now
> A318921, I guess A175046 would be <<agrandir>>?
> As I said in my earlier message today, I haven't heard from him for
> about 15 years. Which was before
> the OEIS became a wiki, and perhaps even before this mailing list was
> created. Claude, are you there?
> There was an obituary for someone of that same name earlier this year,
> which makes me worry.
> Best regards
> Neil J. A. Sloane, President, OEIS Foundation.
> 11 South Adelaide Avenue, Highland Park, NJ 08904, USA.
> Also Visiting Scientist, Math. Dept., Rutgers University, Piscataway, NJ.
> Phone: 732 828 6098; home page: http://NeilSloane.com
> Email: njasloane at gmail.com
> On Sat, Sep 8, 2018 at 10:52 PM, Andrew Weimholt
> <andrew.weimholt at gmail.com> wrote:
>> A318921(A175046(n)) = A001477(n) :-)
>> On Sat, Sep 8, 2018 at 10:22 AM Neil Sloane <njasloane at gmail.com> wrote:
>>> Dear Seq Fans,
>>> I came across an unpublished article by my old friend Claude Lenormand,
>>> which led me to a new French word (raboter) and a new sequence, A318921.
>>> (He was at the eparty for 100000 sequences - you can see his picture there)
>>> He contributed a lot to the OEIS around 2001-2003, but I suspect he is
>>> no longer with us. His email does not answer.
>>> The response from the remote server was:
>>> 550 5.2.1 This mailbox has been blocked due to inactivity
>>> Did any of you know him?
>>> A318921 sounds pretty good: it could be a dirge for his memory.
>>> One could apply the transformation n -> A318921(n) = raboter(n) to
>>> any sequence. I created two examples, A319922 and A318923 (Fibonacci
>>> and primes).
>>> Some time I will scan his article, and add it to A318921.
>>> Seqfan Mailing list - http://list.seqfan.eu/
>> Seqfan Mailing list - http://list.seqfan.eu/
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