The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A024898 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A024898

Positive integers k such that 6*k - 1 is prime.
(history; published version)

#54 by Charles R Greathouse IV at Thu Sep 08 08:44:48 EDT 2022

PROG

(MAGMAMagma) [n: n in [0..1000]| IsPrime(6*n-1)]; // Vincenzo Librandi, Nov 20 2010

Discussion

Thu Sep 08

08:44

OEIS Server: https://oeis.org/edit/global/2944

#53 by Bruno Berselli at Tue Mar 06 11:44:48 EST 2018

STATUS

editing

approved

#52 by Bruno Berselli at Tue Mar 06 11:44:45 EST 2018

NAME

Positive integers k such that 6k 6*k - 1 is prime.

STATUS

approved

editing

#51 by Bruno Berselli at Tue Mar 06 11:44:32 EST 2018

STATUS

reviewed

approved

#50 by Joerg Arndt at Tue Mar 06 11:43:28 EST 2018

STATUS

proposed

reviewed

#49 by Joerg Arndt at Tue Mar 06 11:43:22 EST 2018

STATUS

editing

proposed

#48 by Joerg Arndt at Tue Mar 06 11:43:00 EST 2018

COMMENTS

For each number k in this sequence, there are no positive integers (x,y) such that k = 6xy + x - y. - Pedro Caceres, Jan 22 2018

STATUS

proposed

editing

Discussion

Tue Mar 06

11:43

Joerg Arndt: Comment is even wrong, e.g., for the term 5.

#47 by Alois P. Heinz at Tue Mar 06 09:35:37 EST 2018

STATUS

editing

proposed

#46 by Alois P. Heinz at Tue Mar 06 09:35:31 EST 2018

STATUS

proposed

editing

#45 by Michel Marcus at Sun Feb 11 01:06:48 EST 2018

STATUS

editing

proposed

Discussion

Sun Feb 11

04:32

Joerg Arndt: Looks (true but) silly to me: 6*(6*x*y + x - y)-1 = (6*x - 1)*(6*y + 1).

08:50

Pedro Caceres: Joerg, that is the proof of my comment. Together with similar proofs for 6k+1 primes make possible new algorithms for primality and factoring. Thanks

Tue Mar 06

09:35

Alois P. Heinz: The same is true for (36*x*y + x - 6*y), (36*x*y + 6*x - y), ... all rather trivial.