The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A023308

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A023308

Primes that remain prime through 4 iterations of the function f(x) = 3x + 4.
(history; published version)

#32 by Charles R Greathouse IV at Thu Sep 08 08:44:47 EDT 2022

PROG

(MAGMAMagma) [n: n in [1..1000000] | IsPrime(n) and IsPrime(3*n+4) and IsPrime(9*n+16) and IsPrime(27*n+52) and IsPrime(81*n+160)] // Vincenzo Librandi, Aug 04 2010

Discussion

Thu Sep 08

08:44

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

#31 by Andrew Howroyd at Fri Feb 12 13:21:09 EST 2021

STATUS

reviewed

approved

#30 by Michel Marcus at Fri Feb 12 12:47:39 EST 2021

STATUS

proposed

reviewed

#29 by Jon E. Schoenfield at Fri Feb 12 12:36:13 EST 2021

STATUS

editing

proposed

#28 by Jon E. Schoenfield at Fri Feb 12 12:36:10 EST 2021

NAME

Numbers k such Primes that k remains remain prime through 4 iterations of the function f(x) = 3x + 4.

COMMENTS

k, 3k Primes p such that 3*p+ 4, 9k 9*p+ 16, 27k 27*p+ 52 and 81k 81*p+ 160 are also primes. - Vincenzo Librandi, Aug 04 2010

STATUS

approved

editing

#27 by N. J. A. Sloane at Fri Dec 07 19:14:30 EST 2018

STATUS

proposed

approved

#26 by Jon E. Schoenfield at Fri Dec 07 16:30:08 EST 2018

STATUS

editing

proposed

#25 by Jon E. Schoenfield at Fri Dec 07 16:30:05 EST 2018

NAME

Numbers n k such that n k remains prime through 4 iterations of the function f(x) = 3x + 4.

COMMENTS

n, 3n k, 3k + 4, 9n 9k + 16, 27n 27k + 52 and 81n 81k + 160 are primes. - Vincenzo Librandi, Aug 04 2010

STATUS

proposed

editing

#24 by Muniru A Asiru at Fri Dec 07 15:52:00 EST 2018

STATUS

editing

proposed

#23 by Muniru A Asiru at Fri Dec 07 15:51:52 EST 2018

MAPLE

select(n->isprime(n) and isprime(3*n+4) and isprime(9*n+16) and isprime(27*n+52) and isprime(81*n+160), [$1..760000]); # Muniru A Asiru, Dec 07 2018

PROG

(GAP) Filtered([1..760000], n->IsPrime(n) and IsPrime(3*n+4) and IsPrime(9*n+16) and IsPrime(27*n+52) and IsPrime(81*n+160)); # Muniru A Asiru, Dec 07 2018

STATUS

proposed

editing