This site is supported by donations to The OEIS Foundation.

 Annual Appeal: Please make a donation to keep the OEIS running. In 2018 we replaced the server with a faster one, added 20000 new sequences, and reached 7000 citations (often saying "discovered thanks to the OEIS"). Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A253854 Numbers b such that b^131072 + 1 is prime. 6
 1, 62722, 130816, 228188, 386892, 572186, 689186, 909548, 1063730, 1176694, 1361244, 1372930, 1560730, 1660830, 1717162, 1722230, 1766192, 1955556, 2194180, 2280466, 2639850, 3450080, 3615210, 3814944, 4085818, 4329134, 4893072, 4974408, 5326454, 5400728, 5471814 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Base values b yielding a generalized Fermat prime b^(2^k)+1 for k=17. The first member exceeding 10^((10^6-1)/2^17) is known to be 42654182. - Jeppe Stig Nielsen, Jan 30 2016 LINKS Jeppe Stig Nielsen, Table of n, a(n) for n = 1..64 C. K. Caldwell, 1560730^131072+1, The Largest Known Primes Merfighters, Table of known GF primes b^n+1 where n(exponent) is at least 8192, Mersenne Wiki J. S. S. Nielsen, Generalized Fermat Primes sorted by base (see table at the bottom of the page) CROSSREFS Cf. A056993, A005574, A006315, A006316, A226528, A226529, A226530, A251597, A244150, A243959. Sequence in context: A205764 A209207 A224649 * A237675 A135430 A049025 Adjacent sequences:  A253851 A253852 A253853 * A253855 A253856 A253857 KEYWORD nonn,hard AUTHOR Felix Fröhlich, Jan 17 2015 EXTENSIONS Missing term a(8) inserted by Jeppe Stig Nielsen, Jul 02 2015 a(13) from Felix Fröhlich, Nov 01 2015 a(14)-a(20) from Jeppe Stig Nielsen, Jan 30 2016 a(21)-a(31) from Jeppe Stig Nielsen, Sep 06 2017 a(1) = 1 inserted by Jeppe Stig Nielsen, Sep 10 2018 STATUS approved

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

Last modified December 17 02:29 EST 2018. Contains 318192 sequences. (Running on oeis4.)