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Revision History for A045447

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Showing entries 1-10 | older changes

A045447

Primes congruent to {0, 5} mod 7.
(history; published version)

#12 by Charles R Greathouse IV at Thu Sep 08 08:44:56 EDT 2022

PROG

(MAGMAMagma) [ p: p in PrimesUpTo(2000) | p mod 7 in {0, 5} ]; // Vincenzo Librandi, Aug 13 2012

Discussion

Thu Sep 08

08:44

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

#11 by Jon E. Schoenfield at Sun Mar 08 23:19:17 EDT 2020

STATUS

editing

approved

#10 by Jon E. Schoenfield at Sun Mar 08 23:19:14 EDT 2020

AUTHOR

N. J. A. Sloane.

STATUS

approved

editing

#9 by Harvey P. Dale at Sat Jun 24 14:57:21 EDT 2017

STATUS

editing

approved

#8 by Harvey P. Dale at Sat Jun 24 14:57:17 EDT 2017

COMMENTS

Because 7 is the only prime congruent to 0 mod 7, it is more efficient to search only for primes that are congruent to 5 mod 7 and then insert 7 as the second term of the sequence (see the second Mathematica program below). - Harvey P. Dale, Jun 24 2017

MATHEMATICA

Insert[Select[Prime[Range[500]], Mod[#, 7]==5&], 7, 2] (* Harvey P. Dale, Jun 24 2017 *)

STATUS

approved

editing

#7 by Joerg Arndt at Mon Aug 13 06:32:19 EDT 2012

STATUS

proposed

approved

#6 by Vincenzo Librandi at Mon Aug 13 06:08:56 EDT 2012

STATUS

editing

proposed

#5 by Vincenzo Librandi at Mon Aug 13 06:08:40 EDT 2012

LINKS

Vincenzo Librandi, <a href="/A045447/b045447.txt">Table of n, a(n) for n = 1..1000</a>

MATHEMATICA

Select[Prime[Range[200]], MemberQ[{0, 5}, Mod[#, 7]]&] (* Vincenzo Librandi, Aug 13 2012 *)

PROG

(MAGMA) [ p: p in PrimesUpTo(2000) | p mod 7 in {0, 5} ]; // Vincenzo Librandi, Aug 13 2012

CROSSREFS

Cf. A000040.

KEYWORD

nonn,easy

STATUS

approved

editing

#4 by Russ Cox at Fri Mar 30 16:48:19 EDT 2012

AUTHOR

_N. J. A. Sloane (njas(AT)research.att.com)_.

Discussion

Fri Mar 30

16:48

OEIS Server: https://oeis.org/edit/global/110

#3 by N. J. A. Sloane at Fri Feb 27 03:00:00 EST 2009

KEYWORD

nonn,new

nonn

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com).