# [seqfan] Re: Getting an integer sequence for a specific song

Gordon Charlton gordonrcharlton at gmail.com
Wed Jun 19 16:29:54 CEST 2019

```Hi,

I did make quite a meal of the permutations code - I've just started learning Python, so hopefully future code won't be quite so verbose. BASIC really isn't ideal for that stuff, but it was convenient at the time.

Um, target audience will be using a variety of platforms, so my talk will be as platform agnostic as I can manage. Hence my focussing on easily described sequences. (Also it fits in with the opening quote from Ada Lovelace - "music of any degree of extent or complexity" - there's something very satisfying about producing infinite complexity and extent from such very short algorithms.)

Gordon

> On 19 Jun 2019, at 09:38, Antti Karttunen <antti.karttunen at gmail.com> wrote:
>
>> On 6/18/19, Gordon Charlton <gordonrcharlton at gmail.com> wrote:
>> Link to notes for a talk I am preparing on this subject.
>>
>> https://www.dropbox.com/s/f060yaybdpj9dk0/endless%20rivers%20talk.pdf
>>
>> Featured sequences - Collatz, Kolakoski, Fibonacci & lexicographical list of
>> permutations.
>
> Thanks!
>
> for further inspiration?
>
> The "vertical binary reading" of Fibonacci numbers is the thing I
> encountered in 1998, see https://oeis.org/A036286 (maybe the binary
> pattern was mentioned somewhere in Wolfram's papers or on Weinstein's
> World of Mathematics site, although the NKS-book wasn't published
> until 2002).
>
> Note that the lexicographical list of permutations is actually
> slightly harder to generate than simple A060117 / A060118 ("linear
> time algorithm") that I use for example in my green music box, where
> the conversion from a factorial expansion to permutation is actually
> done in a single cycle with pure combinational logic. (No timewise
> need for that, but it was a nice thing to do!)
>
> Change ringing is a much explored field for finding permutation walk
> algorithms, and I guess there would be potential for further
> developing them (also for infinite variants).
> "Plain Bob" must be plainest of them, but see the links:
> https://oeis.org/search?q=plain+bob&sort=&language=&go=Search
> (Beware of exotic terminology, quite different from those of group
> theoreticians!)
>
> For infinite variants, I started playing with the idea here:
> https://oeis.org/A060135
> That link to my page has been dead for a long time, but fortunately,
> the Internet Archive saves:
> https://web.archive.org/web/20090213151317/http://ndirty.cute.fi/~karttu/matikka/permgraf/troctahe.htm
>
> Then, in the same directory, see:
> https://web.archive.org/web/20090214164542/http://ndirty.cute.fi/~karttu/matikka/permgraf/cswtab.htm
> J. H. Conway, N. J. A. Sloane and A. R. Wilks, Gray Codes for
> Reflection Groups, Graphs and Combinatorics, 5 (1989), pp. 315-325.
> and
> F. Ruskey and Carla Savage, Hamilton Cycles which Extend Transposition
> Matchings in Cayley Graphs of Sn, SIAM Journal on Discrete
> Mathematics, 6 (1993) 152-166.
>
> (for anybody wanting to jump into that rabbit's hole!)
>
>>
>> Target audience - experimental musicians with programming skills.
>
> Do you know what platforms they are using? Overtone, for example?
>
>
> Best regards,
>
> Antti
>
>> Note I do
>> not consider myself a mathematician. If you happen to notice any errors of
>> terminology in the text, please let me know off-list. Thank you.
>>
>> Gordon
>>
>>
>> On 17 Jun 2019, at 11:44, aleksisto <aleksisto at gmail.com> wrote:
>>
>>>> I think it's the opposite direction, turning sequences (and other
>>>> mathematical structures) to songs that's much more fertile field in
>>>> the long run.
>>> Using Parsons code(https://en.wikipedia.org/wiki/Parsons_code) you can
>>> search for any melody in the pi digits sequence, for instance.
>>>
>>> aleksisto
>>>
>>>
>>> --
>>> Seqfan Mailing list - http://list.seqfan.eu/
>>
>> --
>> Seqfan Mailing list - http://list.seqfan.eu/
>>

```