[seqfan] Re: A015938 and A015939

[RGWv]

Dear Max,

    I am surprised that you found this so difficult. I was able to do this 
while at Flight Level 340 on my way to ATL using a simply calculator. Anyway 
I see that by the time I got back, several others have fixed it.

Sincerely yours, Bob.

-----Original Message----- 
From: Max Alekseyev
Sent: Thursday, August 04, 2011 9:08 AM
To: Sequence Fanatics Discussion list
Subject: [seqfan] Re: A015938 and A015939

Hi Bob,

Here is another sequence whose definition does not make sense to me:

A015943 Numbers n such that n | 2^n + n/2 (mod n) for even n.

Could you please clarify what it supposed to mean?

Thanks,
Max

On Tue, Aug 2, 2011 at 8:16 AM, RGWv <rgwv at rgwv.com> wrote:
> Dear Neil,
>
>   I have added the Mathematica coding to the sequence in the hope that 
> doing
> so will help explain what is going on. It is:
>
> f[n_] := Block[{k = 2^n + 1}, While[ PowerMod[2, k, k] != PowerMod[2, n, 
> k],
> k++]; k]; Array[f, 30]
>
>   I hope this helps.
>
> Bob.
>
> -----Original Message----- From: N. J. A. Sloane
> Sent: Monday, August 01, 2011 10:29 AM
> To: seqfan at list.seqfan.eu
> Cc: njas at research.att.com ; rgwv at rgwv.com
> Subject: Re: [seqfan] Re: A015938 and A015939
>
> Bob Wilson, the author of these two sequences,
> is a memeber of this list, so hopefully he
> will be able to clear this up. I will copy this
> directly to him.
> Neil
>
>> Date: Mon, 1 Aug 2011 14:25:21 +0300
>> From: Georgi Guninski <guninski at guninski.com>
>> To: Sequence Fanatics Discussion list <seqfan at list.seqfan.eu>
>
>> On Mon, Aug 01, 2011 at 11:20:00AM +0400, Max Alekseyev wrote:
>>>
>>> Does anybody understand how A015938 and A015939 were obtained?
>>> The definitions do not seem to match the listed terms.
>>> In particular, the definition of A015938 should have produced the
>>> sequence of all ones.
>>> Regards,
>>> Max
>>>
>
>> The numbers in A015939 contain powers of 2 contradicting "not of form
>> 2^n"
>
>
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>
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>

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