# [seqfan] Re: A174397 and primes with negative value.

Maximilian Hasler maximilian.hasler at gmail.com
Sat Mar 20 13:25:30 CET 2010

```Well as long as almost all terms are positive, and an explicative
remark is added, one might consider it as tolerable,
A103802 A103803 A103804 A103805 A103806 A103807

but I must admit that I don't see well the motivation for the
particular case of chosen offsets (9, 15, 21, 27, 33, and the
combination "+/- 27 and +/- 33") in these sequences
(e.g. A103807 Primes p such that p, 2p+/-27 and 2p+/-33 are all primes.)

the motivation ?

As to

%N A050267 Primes of the form 47*n^2-1701*n+10181.

and similar sequences, the terms are not correct since according to
the definition, this is a list of numbers with some property, and they
must be listed in increasing size.

In the concrete case at hand, the sequence should read :

A050267 =
-5209, -5171, -5153, -5039, -5003, -4813, -4759, -4493, -4421, -4079,
-3989, -3571, -3463, -2969, -2843, -2273, -2129, -1483, -1321, -599,
-419, 379, 577, 1451, 1667, 2617, 2851, 3877, 4129, 5231, 5501, 6679,
6967, 8221, 8527, ...

then decide whether / why "n" should take only nonnegative values.

Maximilian

On Sat, Mar 20, 2010 at 1:03 PM, zak seidov <zakseidov at yahoo.com> wrote:
> And  another case of negative primes
>
> %N A050267 Primes of the form 47*n^2-1701*n+10181.
>
> %V A050267 10181,8527,6967,5501,4129,2851,1667,577,-419,-1321,-2129,-2843,-3463,
>               -3989,-4421,
> %W A050267 -4759,-5003,-5153,-5209,-5171,-5039,-4813,-4493,-4079,-3571,-2969,-2273,
>               -1483,-599,
> %X A050267 379,1451,2617,3877,5231,6679,8221,9857,11587,13411,15329,17341,19447
>
>
> Zak
>
>
> ----- Original Message ----
> From: zak seidov <zakseidov at yahoo.com>
> To: seqfaneu <seqfan at seqfan.eu>
> Sent: Sat, March 20, 2010 1:58:12 PM
> Subject: [seqfan] Re: A174397 and primes with negative value.
>
> But we have several "negative primes" in OEIS:
>
> A088005            Numbers whose abundance is either a positive or a negative prime number.
>
> A125211            a(n) = total number of positive and negative primes of the form k! - n.
>
> A125212            a(n) = numbers n such that no positive and no negative prime exists of the form k! - n; or A125211(n) = 0.
>
> A088006            Abundance values which are either positive or negative prime numbers.
>
> A002143 (see rf. ET Ordman)
>
> A125236   (see %e )
>
> A103807  Primes p such that p, 2p+/-27 and 2p+/-33 are all primes. (my sequence ?!)
>
> Remove or not remove - that is the Q ;-)
>
> Zak
>
>
>
>
>
>
> ----- Original Message ----
> From: N. J. A. Sloane <njas at research.att.com>
> To: seqfan at list.seqfan.eu
> Sent: Sat, March 20, 2010 6:21:21 AM
> Subject: [seqfan] Re: A174397 and primes with negative value.
>
> Yes,  in the OEIS primes are positive.  I'm going to reject this sequence:
>
> %I A174397
> %S A174397 29,2,47,241,1181,4691,15307,24023,29401,42437,117043,226231,
> %T A174397 273827,299941,703883,1441523,2246501,2569691,3441121,4328773,
> %U A174397 5733173,6329387,8362973,10791191,12006223,13649033,14703167
> %V A174397 29,2,-47,-241,-1181,-4691,-15307,-24023,-29401,-42437,-117043,-226231,
> %W A174397 -273827,-299941,-703883,-1441523,-2246501,-2569691,-3441121,-4328773,
> %X A174397 -5733173,-6329387,-8362973,-10791191,-12006223,-13649033,-14703167
> %N A174397 Primes of the form p=(n+2)^3-(n+1)^3-n^3.
> %Y A174397 Select[Table[(n+2)^3-(n+1)^3-n^3, {n, 6!}], PrimeQ[ # ]&]
> %Y A174397 Adjacent sequences: A174394 A174395 A174396 this_sequence A174398 A174399 A174400
> %K A174397 nonn,new
> %O A174397 1,1
>
>
> Neil
>
>
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