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%I #24 Jan 17 2019 10:08:17
%S 1,5,7,9,15,19,21,35,37,39,41,49,69,111,115,141,159,181,201,217,487,
%T 567,677,765,811,841,917,1279,1407,1505,1521,1587,2047,2469,2649,3019,
%U 7427,10257,33685,34479,35177,43641,49211,65031,84907,90231,95021,124375,176425,224947,382441,451367
%N Numbers k such that 139*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[139*2^# - 1] & ] (* _Robert Price_, Dec 23 2018 *)
%o (PARI) is(n)=ispseudoprime(139*2^n-1) \\ _Charles R Greathouse IV_, Jun 13 2017
%K hard,nonn
%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(49)-a(52) from the Wilfrid Keller link by _Robert Price_, Dec 23 2018
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