[seqfan] Re: A220952 "unkn" (author Don Knuth, Feb 20, 2013) - continuation?

[Paolo Bonzini]

On 25/08/2017 03:41, Rob Pratt wrote:
> American Mathematical Monthly Problem 11733: A Twisted Enumeration of the Positive Integers
> Solution in Volume 123, No. 1 (January 2016)

PDF at https://lupucezar.files.wordpress.com/2011/02/amer-math-monthly-123-1-97.pdf

It looks like Georg's solution is correct: "Similarly 48
([base-5] expansion 143) is adjacent to 47 (expansion 142])
and 73 (expansion 243)."

The solution gives a(1000000)=667778.  Georg, what do you get? :)

Paolo

> -----Original Message-----
> From: SeqFan [mailto:seqfan-bounces at list.seqfan.eu] On Behalf Of israel at math.ubc.ca
> Sent: Thursday, August 24, 2017 8:17 PM
> To: Sequence Fanatics Discussion list <seqfan at list.seqfan.eu>
> Subject: [seqfan] Re: A220952 "unkn" (author Don Knuth, Feb 20, 2013) - continuation?
> 
> EXTERNAL
> 
> Since the sequence was contributed on Feb 20 2013, I would suspect it has already been published.
> 
> Cheers,
> Robert
> 
> On Aug 24 2017, Neil Sloane wrote:
> 
>> I'm a bit skeptical that that is the correct explanation
>>
>> The way the sequence was entered suggests that Don Knuth proposed it as 
>> a problem in some journal, and so did not want to give the explanation 
>> before the solution appeared in the journal.
>>
>> Presumably when the journal appears, someone will make the connection 
>> with the OEIS entry.
>>
>> Best regards
>> Neil
>>
>> 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 Thu, Aug 24, 2017 at 5:50 PM, Georg.Fischer 
>> <georg.fischer at t-online.de> wrote:
>>> Dear Neil, dear SeqFans,
>>>
>>> It seems to me that sequence A220952 never has received any comment.
>>> Maybe Neil knows more.
>>>
>>> I think that a(n=0..125) should read: 1, 2,3,4,9, 
>>> 14,19,18,17,16,11,12,13,8,7,6,5,10,15,20,21,22,23,24,
>>> 49,74,99,98,97,96,95,90,85,80,81,82,83,88,87,86,91,92,93,94,89,84,79,
>>> 78,77,76,51, 
>>> 52,53,54,59,64,69,68,67,66,61,62,63,58,57,56,55,60,65,70,71,72,73,48,
>>> 47,46,45,40, 
>>> 35,30,31,32,33,38,37,36,41,42,43,44,39,34,29,28,27,26,25,50,75,100,10
>>> 1,102,103,104, 
>>> 109,114,119,118,117,116,111,112,113,108,107,106,105,110,115,120,121,1
>>> 22,123,124,
>>> 249
>>>
>>> Please have a look at my page
>>> <http://www.teherba.org/index.php/OEIS/A220952> where you find some 
>>> explanations and links to the plots which show letter "Z" shaped 
>>> structures in kind of "fractal"
>>> nesting.
>>>
>>> I do not dare to add a comment to the sequence until somebody finds 
>>> this reasonable. If my continuation is the desired one, I would of 
>>> cause be very interested in additional interpretations.
>>>
>>> Best regards - Georg Fischer
>>>
>>>
>>> --
>>> Seqfan Mailing list - http://list.seqfan.eu/
>>
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>>
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