# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/

Search: id:a050855
Showing 1-1 of 1

%I A050855 #18 Jan 17 2019 10:08:17
%S A050855 2,9,12,17,20,21,50,53,132,168,341,360,381,501,1065,1169,1545,2109,
%T A050855 2520,2661,3149,4077,11252,21588,21692,39509,52685,67196,87708,232436,
%U A050855 372312,417818,481385,507833
%N A050855 Numbers n such that 207*2^n-1 is prime.
%C A050855 Also in the sequence: 643478 - Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 02 2008
%H A050855 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 A050855 Wilfrid Keller, <a href="http://www.prothsearch.com/riesel2.html">List of primes k.2^n - 1 for k < 300</a>
%H A050855 <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>
%H A050855 Kosmaj, <a href="http://www.15k.org/riesellist.html">Riesel list k<300</a>.
%o A050855 (PARI) is(n)=ispseudoprime(207*2^n-1) \\ _Charles R Greathouse IV_, Jun 13 2017
%K A050855 hard,nonn
%O A050855 1,1
%A A050855 _N. J. A. Sloane_, Dec 29 1999
%E A050855 More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 02 2008

# Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE