%I #24 Jan 17 2019 10:08:17
%S 1,5,33,97,121,125,305,445,473,513,1581,3077,3517,6345,8797,15265,
%T 16641,32185,32581,43905,77025,84377,202345,230777,234401,473073,
%U 802321,869073
%N Numbers k such that 157*2^k-1 is prime.
%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 Kosmaj, <a href="http://www.15k.org/riesellist.html">Riesel list 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 23 2018 *)
%o (PARI) is(n)=ispseudoprime(157*2^n-1) \\ _Charles R Greathouse IV_, Jun 13 2017
%K hard,nonn,more
%O 1,2
%A _N. J. A. Sloane_, Dec 29 1999
%E More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 02 2008
%E a(27)-a(28) from the Wilfrid Keller link by _Robert Price_, Dec 23 2018