[seqfan] Re: A015938 and A015939

[RGWv]

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"