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A253854 Numbers b such that b^131072 + 1 is prime. 3
62722, 130816, 228188, 386892, 572186, 689186, 909548, 1063730, 1176694, 1361244, 1372930, 1560730, 1660830, 1717162, 1722230, 1766192, 1955556, 2194180, 2280466 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

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

Table of n, a(n) for n=1..19.

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)

PrimeGrid, PrimeGrid Primes - (GFN131072) Generalized Fermat Prime Search n=131072

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,more

AUTHOR

Felix Fröhlich, Jan 17 2015

EXTENSIONS

Missing term a(7) inserted by Jeppe Stig Nielsen, Jul 02 2015

a(12) from Felix Fröhlich, Nov 01 2015

a(13)-a(19) from Jeppe Stig Nielsen, Jan 30 2016

STATUS

approved

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Last modified April 25 14:30 EDT 2017. Contains 285414 sequences.