%I #44 Sep 11 2020 14:30:15

%S 1,278,614,892,898,1348,1494,1574,1938,2116,2122,2278,2762,3434,4094,

%T 4204,4728,5712,5744,6066,6508,6930,7022,7332,8524,8644,8762,8808,

%U 9024,9142,9412,10892,12206,13220,13222,13246,13370,13738,14114,14930

%N Numbers k such that k^256 + 1 is prime.

%D Harvey Dubner, Generalized Fermat primes, J. Recreational Math., 18 (1985): 279-280.

%H Simon Plouffe, <a href="/A056995/b056995.txt">Table of n, a(n) for n = 1..10000</a> (1000 first terms from T. D. Noe)

%H Yves Gallot, <a href="http://yves.gallot.pagesperso-orange.fr/primes/GFN/GFN256.html">Generalized Fermat Prime Search</a>.

%H Simon Plouffe, <a href="/A056995/a056995_1.txt">146309 terms</a>

%t Do[ k = 1; While[ PowerMod[ n, 256, 2*k*256 + 1 ] != 2*k*256 && k < 10^3, k++ ]; If[ k == 10^3 && PrimeQ[ n^256 + 1 ], Print[ n ] ], {n, 2, 15000, 2} ]

%o (PARI) isA056995(n) = isprime(n^256+1) \\ _Michael B. Porter_, Apr 01 2010

%Y Cf. A005574, A000068, A006314, A006313, A006315, A006316, A056994, A057465, A057002, A088361, A088362, A226528, A226529, A226530, A251597, A253854, A244150, A243959, A321323.

%K nonn

%O 1,2

%A _Robert G. Wilson v_, Sep 06 2000