login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A253854 Numbers b such that b^131072 + 1 is prime. 22

%I #64 Apr 03 2023 10:36:13

%S 1,62722,130816,228188,386892,572186,689186,909548,1063730,1176694,

%T 1361244,1372930,1560730,1660830,1717162,1722230,1766192,1955556,

%U 2194180,2280466,2639850,3450080,3615210,3814944,4085818,4329134,4893072,4974408,5326454,5400728,5471814

%N Numbers b such that b^131072 + 1 is prime.

%C Base values b yielding a generalized Fermat prime b^(2^k)+1 for k=17.

%C The first member exceeding 10^((10^6-1)/2^17) is known to be 42654182. - _Jeppe Stig Nielsen_, Jan 30 2016

%H Jeppe Stig Nielsen, <a href="/A253854/b253854.txt">Table of n, a(n) for n = 1..515</a> (from a massive computation by PrimeGrid).

%H C. K. Caldwell, <a href="https://t5k.org/primes/page.php?id=120493">1560730^131072+1</a>, The Largest Known Primes

%H C. K. Caldwell, <a href="https://primes.utm.edu/primes/search.php?Description=%25%5E131072%2B1&amp;OnList=all&amp;Number=2000&amp;Style=HTML">Search result %^131072+1</a>.

%H J. S. S. Nielsen, <a href="http://jeppesn.dk/generalized-fermat.html">Generalized Fermat Primes sorted by base</a> (see table at the bottom of the page)

%H PrimeGrid, <a href="http://www.primegrid.com/primes/primes.php?project=GFN131072">PrimeGrid Primes - (GFN131072) Generalized Fermat Prime Search n=131072</a>

%H PrimeGrid, <a href="https://www.primegrid.com/stats_genefer.php">Generalized Fermat statistics</a>

%Y Cf. A056993, A005574, A000068, A006314, A006313, A006315, A006316, A056994, A056995, A057465, A057002, A088361, A088362, A226528, A226529, A226530, A251597, A244150, A243959, A321323.

%K nonn,hard

%O 1,2

%A _Felix Fröhlich_, Jan 17 2015

%E Missing term a(8) inserted by _Jeppe Stig Nielsen_, Jul 02 2015

%E a(13) from _Felix Fröhlich_, Nov 01 2015

%E a(14)-a(20) from _Jeppe Stig Nielsen_, Jan 30 2016

%E a(21)-a(31) from _Jeppe Stig Nielsen_, Sep 06 2017

%E a(1) = 1 inserted by _Jeppe Stig Nielsen_, Sep 10 2018

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 18 22:18 EDT 2024. Contains 371782 sequences. (Running on oeis4.)