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

zak seidov zakseidov at yahoo.com
Sat Mar 20 12:58:12 CET 2010


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
Cc: 4vladimir at gmail.com
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
%A A174397 Vladimir Orlovsky (4vladimir(AT)gmail.com), Mar 18 2010


Neil


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