# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a050564 Showing 1-1 of 1 %I A050564 #18 Jan 17 2019 10:08:17 %S A050564 2,4,14,26,58,60,64,100,122,212,566,638,1214,2080,4852,5356,5720,7044, %T A050564 8320,8556,10684,14584,39016,47972,72008,217956,223512,387680,441528, %U A050564 607920,855770 %N A050564 Numbers n such that 77*2^n-1 is prime. %C A050564 1467554 is also a member. - Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 02 2008 %H A050564 Ray Ballinger and Wilfrid Keller, List of primes k.2^n + 1 for k < 300 %H A050564 Wilfrid Keller, List of primes k.2^n - 1 for k < 300 %H A050564 Index entries for sequences of n such that k*2^n-1 (or k*2^n+1) is prime %H A050564 Kosmaj, Riesel list k<300. %o A050564 (PARI) is(n)=ispseudoprime(77*2^n-1) \\ _Charles R Greathouse IV_, Jun 13 2017 %K A050564 hard,nonn %O A050564 1,1 %A A050564 _N. J. A. Sloane_, Dec 29 1999 %E A050564 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