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%I #27 Apr 05 2020 00:35:53
%S 8,12,14,24,32,134,252,272,404,1460,1776,8510,14280,14396,17736,21284,
%T 84056,147036,490772,963590,1920152,2407958
%N Numbers k such that 157*2^k+1 is prime.
%H Ray Ballinger, <a href="http://www.prothsearch.com/index.html">Proth Search Page</a>
%H Ray Ballinger and Wilfrid Keller, <a href="http://www.prothsearch.com/riesel1.html">List of primes k.2^n + 1 for k < 300</a>
%H Wilfrid Keller, <a href="http://www.prothsearch.com/riesel2.html">List of primes k.2^n - 1 for k < 300</a>
%H <a href="/index/Pri#riesel">Index entries for sequences of n such that k*2^n-1 (or k*2^n+1) is prime</a>
%t Select[Range[1000], PrimeQ[157*2^# + 1] & ] (* _Robert Price_, Dec 18 2018 *)
%o (PARI) is(n)=ispseudoprime(157*2^n+1) \\ _Charles R Greathouse IV_, Jun 13 2017
%K nonn,hard,more
%O 1,1
%A _N. J. A. Sloane_.
%E a(17)-a(21) from the Ray Ballinger and Wilfrid Keller link by _Robert Price_, Dec 18 2018
%E a(22) from _Jeppe Stig Nielsen_, Apr 04 2020
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