[seqfan] Re: Arabic Poetry Sequences

Alonso Del Arte alonso.delarte at gmail.com
Fri Aug 30 19:57:09 CEST 2019


In a lot of the examples, there is one distinctive term that enables one to
quickly find the relevant entry with just that one term. In other cases,
three or four terms may be necessary, but still short of the six usually
suggested to find the more obviously mathematical sequences.

I doubt there are many sequences of 0s and 1s in the examples. The example
of A061745, Unicode code points for Han digits, made me think of the
Unicode character Boolean property isDigit().

(0 to 255).map(Character.isDigit(_).compare(false))

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0

This sequence is presumably well defined through *a*(65535). But after the
1s shown above, it might be all 0s until we get to the Arabic-Indic digits
sub-block of the Arabic block.

(1630 to 1649).map(Character.isDigit(_).compare(false))

0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0

This sequence is not in the OEIS and it doesn't need to be.

Al

P.S. For the curious, here's the Scastie snippet:
https://scastie.scala-lang.org/6JVa3dClQ9qgSYX9zzuzHg

On Fri, Aug 30, 2019 at 5:50 AM Peter Luschny <peter.luschny at gmail.com>
wrote:

> GR> In general, I'm personally against introducing further
> non-mathematical sequences in OEIS.
>
> A few years ago, I would have said precisely the same thing.
> Then I read Charles R. Greathouse, The multi-faceted reach of
> the OEIS.
> http://oeis.org/wiki/The_multi-faceted_reach_of_the_OEIS
>
> It made me think. There are so many sequences in the OEIS
> that are not mathematical in nature, although, expressed as
> a numerical sequence, they can superficially make such an
> impression. Just a couple of examples:
>
> A080915 Number of electrons in outermost electron shell
> (valence electrons) in chemical element number n.
>
> A005960 Number of acyclic disubstituted alkanes with n
> carbon atoms and distinct substituents.
>
> A003678 Decimal expansion of the SI unit c.
>
> A119247 Contains the ISO human tooth numbering sequence.
>
> https://en.wikipedia.org/wiki/Dental_notation#ISO_System_by_the_World_Health_Organization
>
> A115020 Alzheimer's disease test.
>
> A175726 Age of Biblical generations from Adam to Noah according
> to the Hebrew Bible.
>
> A061745 Unicode codes for the Han digits.
>
> A054356 The Five Hysterical Girls Theorem (author Antti Karttunen).
>
> A038674 A finite series from the lyrics of La Farolera, a Latin
> American traditional children's song.
>
> More lyrics:
> http://oeis.org/wiki/The_multi-faceted_reach_of_the_OEIS#Lyrics
>
> Certainly not with all, but with some I find that they deserve
> their place in the OEIS. And that the criterion should not be
> whether they come from the natural sciences; instead whether
> they are connected to culture in a more general sense.
>
> On the other hand, almost every day, I read suggestions for
> sequences consisting of playful chains of symbols that comply
> with rules that are far away from any mathematical content.
> Sometimes I find them so absurd that I would reject them
> instantly (in fact, in such cases, I often abstain from any
> comment; later, I see them accepted in large numbers).
>
> And there is a third aspect I would like to mention:
> The influence poetry and rhythm had and has on mathematics
> and combinatorics. I suggest the section already mentioned
> by Antti, DEK, vol 4, fasc. 4.
>
> We should be aware that these things may have more influence
> in other cultures than the one we belong to. Who doesn't know
> it yet I suggest the remarks of Fields Medal winner Manjul
> Bhargava about the mathematics hidden in the rhythms of classical
> Indian music. https://www.youtube.com/watch?v=siFBqH-LaQQ
>
> For these three reasons, I think that the proposed sequences
> have their place in the OEIS. Provided they are accompanied
> by carefully selected references and their encoding is clearly
> explained. Which of course can happen on a blog page that will
> be linked to, as Giovanni suggests.
>
> Peter
>
> --
> Seqfan Mailing list - http://list.seqfan.eu/
>


-- 
Alonso del Arte
Author at SmashWords.com
<https://www.smashwords.com/profile/view/AlonsoDelarte>
Musician at ReverbNation.com <http://www.reverbnation.com/alonsodelarte>



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