The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A128066

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A128066

Numbers k such that (3^k + 4^k)/7 is prime.
(history; published version)

#20 by Michel Marcus at Tue Jan 22 03:51:32 EST 2019

STATUS

reviewed

approved

#19 by Joerg Arndt at Tue Jan 22 03:42:26 EST 2019

STATUS

proposed

reviewed

#18 by Michel Marcus at Tue Jan 22 03:15:12 EST 2019

STATUS

editing

proposed

#17 by Michel Marcus at Tue Jan 22 03:15:07 EST 2019

LINKS

Henri Lifchitz & Renaud Lifchitz, <a href="http://www.primenumbers.net/prptop/searchform.php?form=%284%5Ep%2B3%5Ep%29%2F7">Top probable primes of the form (4^p+3^p)/7</a>

STATUS

proposed

editing

#16 by Jon E. Schoenfield at Tue Jan 22 03:13:27 EST 2019

STATUS

editing

proposed

#15 by Jon E. Schoenfield at Tue Jan 22 03:13:24 EST 2019

NAME

Numbers n k such that (3^n k + 4^nk)/7 is prime.

MAPLE

a:=proc(n) if type((3^n+4^n)/7, integer)=true and isprime((3^n+4^n)/7)=true then n else fi end: seq(a(n), n=1..1500); -_# _Emeric Deutsch_, Feb 17 2007

PROG

/* _Joerg Arndt, _, Mar 27 2011 */

STATUS

approved

editing

#14 by Russ Cox at Sat Mar 31 13:20:35 EDT 2012

AUTHOR

_Alexander Adamchuk (alex(AT)kolmogorov.com), _, Feb 14 2007

Discussion

Sat Mar 31

13:20

OEIS Server: https://oeis.org/edit/global/879

#13 by Russ Cox at Sat Mar 31 10:26:46 EDT 2012

EXTENSIONS

Two more terms (13463 and 23929) found by Lelio R Paula in 2008 corresponding to probable primes with 8105 and 14406 digits. _Jean-Louis Charton (chartonjl(AT)wanadoo.fr), _, Oct 06 2010

Discussion

Sat Mar 31

10:26

OEIS Server: https://oeis.org/edit/global/509

#12 by Russ Cox at Fri Mar 30 17:37:44 EDT 2012

EXTENSIONS

2 more terms from _Farideh Firoozbakht (mymontain(AT)yahoo.com), _, Apr 16 2007

Discussion

Fri Mar 30

17:37

OEIS Server: https://oeis.org/edit/global/181

#11 by Russ Cox at Fri Mar 30 17:36:12 EDT 2012

MAPLE

a:=proc(n) if type((3^n+4^n)/7, integer)=true and isprime((3^n+4^n)/7)=true then n else fi end: seq(a(n), n=1..1500); -_Emeric Deutsch (deutsch(AT)duke.poly.edu), _, Feb 17 2007

EXTENSIONS

3 more terms from _Emeric Deutsch (deutsch(AT)duke.poly.edu), _, Feb 17 2007

Discussion

Fri Mar 30

17:36

OEIS Server: https://oeis.org/edit/global/173