# [seqfan] Re: Reciprocal Recaman

M. F. Hasler oeis at hasler.fr
Sat Nov 16 03:20:18 CET 2013

```But unless we know whether / from where on they differ, it is IMHO not
so useful to create this new sequence without an indication, it will
make editors and contributors loose their time in the future with
suggestions to delete this as duplicate of A2805.
I think it would be as useful to add a comment in A231692 saying "the
denominaters are conjectured to be different from (or: equal to)
A2805.
One could also xref
A203811: Denominators of s(i) = s(i-1) - (1/i)*sign(s(i-1)) with s(1) = 1.
based on a very similar idea (but which differs (more) often).
Maximilian
PS: it seems the two coincide at least up to the 43000+ digit a( n=10^5 ):
{s=t=0;for(n=1,10^5,denominator(s+=(-1)^(n*s<1)/n)!=denominator(t+=1/n)&&return(n))}
does not return...

On Fri, Nov 15, 2013 at 10:06 PM, Neil Sloane <njasloane at gmail.com> wrote:
> Oops! The denominators are A231693...
>
>
> On Fri, Nov 15, 2013 at 7:34 PM, <franktaw at netscape.net> wrote:
>
>> I would be surprised if they are.
>>
>>
>>
>> -----Original Message-----
>> From: David Wilson <davidwwilson at comcast.net>
>> To: 'Sequence Fanatics Discussion list' <seqfan at list.seqfan.eu>
>> Sent: Fri, Nov 15, 2013 6:04 pm
>> Subject: [seqfan] Re: Reciprocal Recaman
>>
>>
>> Do we know for sure that the denominators are A002805?
>>
>>  -----Original Message-----
>>> From: SeqFan [mailto:seqfan-bounces at list.seqfan.eu] On Behalf Of Neil
>>> Sloane
>>> Sent: Friday, November 15, 2013 5:57 AM
>>> To: Sequence Fanatics Discussion list
>>> Subject: [seqfan] Re: Reciprocal Recaman
>>>
>>> I added the numerators of f(n) as A231692. The denominators are
>>>
>> A002805.
>>
>>> I also added this to the Index to Fractions on the Wiki side.
>>> Perhaps someone else (Don?) could add Don's sequence.
>>> Neil
>>>
>>>
>>> On Fri, Nov 15, 2013 at 4:51 AM, Don Reble <djr at nk.ca> wrote:
>>>
>>> > f(0) = 0
>>> >> f(n) = f(n-1) - 1/n if >= 0, else f(n-1) + 1/n.
>>> >>
>>> >> For which n do we have f(n-2) > f(n-1) > f(n)?
>>> >>
>>> >
>>> >    I get
>>> >
>>> >    3 6 13 34 91 264 783 2342 7013 21030 63079 189236 567709 1703124
>>> >    5109367 15328088 45984249
>>> >
>>> >    Since odds and evens alternate, I conclude that no term is triple
>>> >    the previous.
>>> >
>>> > --
>>> > Don Reble  djr at nk.ca
>>> >
>>> >
>>> >
>>> > _______________________________________________
>>> >
>>> > Seqfan Mailing list - http://list.seqfan.eu/
>>> >
>>>
>>>
>>>
>>> --
>>> Dear Friends, I have now retired from AT&T. New coordinates:
>>>
>>> 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.
>>
>>> Email: njasloane at gmail.com
>>>
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>>>
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>>
>>
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>
>
>
> --
> Dear Friends, I have now retired from AT&T. New coordinates:
>
> 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.