# [seqfan] Re: A159559

Benoît Jubin benoit.jubin at gmail.com
Thu Jul 30 17:26:18 CEST 2009

```On Thu, Jul 30, 2009 at 5:00 PM, Alexander Povolotsky<apovolot at gmail.com> wrote:
> FYI  - sequence's author opinion ...
>
> ---------- Forwarded message ----------
> From: Vladimir Shevelev <shevelev at bgu.ac.il>
> Date: Thu, 30 Jul 2009 14:43:39 GMT
> Subject: Re: OEIS Fan's discussion re A159559
> To: Alexander Povolotsky <apovolot at gmail.com>
>
> Very thanks.
>
> In my opinion,  the adding of a(1)=2 is not correct in principle since
> contradicts to the main idea:
> the behavior of the sequence repeats the behavior of the positive
> integers with respect to the property: to be or not to be prime;
> therefore, we begin from a(2)=3.

If we add a(1)=2, then this is the same with the property: to be or
not to be composite.  In both cases, the initial value is the smallest
which is different from the argument (in order not to obtain the
sequence of positive integers).  Therefore the "right" sequence for
the property "to be or not to be prime" is A159698, that is
a(1)=4,a(2)=5...

Anyway, this is not a big change, but imagine someone who makes the
searches "3,5,6,7,8,11" and "2,3,5,6,7,8,11"; only the sequence with
a(1)=2 will appear in both cases.

By the way, the observations I made in my previous message are
essentially contained in Shevelev's paper.

Benoit

>
>
> ----- Original Message -----
> From: Alexander Povolotsky <apovolot at gmail.com>
> Date: Wednesday, July 29, 2009 0:51
> Subject: OEIS Fan's discussion re A159559
> To: shevelev at bgu.ac.il
>
>> FYI - OEIS Fan's discussion re A159559
>> http://list.seqfan.eu/pipermail/seqfan/2009-July/001957.html
>> http://list.seqfan.eu/pipermail/seqfan/2009-July/001960.html
>> http://list.seqfan.eu/pipermail/seqfan/2009-July/001962.html
>> http://list.seqfan.eu/pipermail/seqfan/2009-July/001964.html
>>
>