The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A005385

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A005385

Safe primes p: (p-1)/2 is also prime.
(history; published version)

#195 by Michael De Vlieger at Wed Dec 18 15:05:24 EST 2024

STATUS

reviewed

approved

#194 by Amiram Eldar at Wed Dec 18 14:09:54 EST 2024

STATUS

proposed

reviewed

#193 by Michel Marcus at Wed Dec 18 12:51:44 EST 2024

STATUS

editing

proposed

#192 by Michel Marcus at Wed Dec 18 12:51:33 EST 2024

LINKS

B. Benoit Cloitre, <a href="https://web.archive.org/web/20150923071043/http://www.ebahbcmathematics.commonsite-orange.br/content/ABAAAgYboAKfr/fractal-order-of-primesFractalOrderOfPrimes.pdf">On the fractal behavior of primes</a>, 2011.

STATUS

approved

editing

#191 by Joerg Arndt at Wed Feb 07 01:14:49 EST 2024

STATUS

editing

approved

#190 by Paolo P. Lava at Tue Feb 06 07:30:04 EST 2024

FORMULA

a(n) = A077065(n) + 1. - Paolo P. Lava, Jun 10 2013

STATUS

approved

editing

#189 by Charles R Greathouse IV at Thu Sep 08 08:44:33 EDT 2022

PROG

(MAGMAMagma) [p: p in PrimesUpTo(3000) | IsPrime((p-1) div 2)]; // Vincenzo Librandi, Jul 06 2015

Discussion

Thu Sep 08

08:44

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

#188 by Peter Luschny at Mon Jun 14 13:39:18 EDT 2021

STATUS

proposed

approved

#187 by M. F. Hasler at Mon Jun 14 10:58:53 EDT 2021

STATUS

editing

proposed

#186 by M. F. Hasler at Mon Jun 14 10:53:52 EDT 2021

COMMENTS

It is conjectured that there are infinitely many safe primes, and their estimated asymptotic density ~ 2C/(ln log n)^2 (where C = 0.66... is the twin prime constant A005597) converges to the actual value as far as we know. - M. F. Hasler, Jun 14 2021

STATUS

proposed

editing

Discussion

Mon Jun 14

10:58

M. F. Hasler: Fixed!