A050562 - OEIS

%I #18 Jan 17 2019 10:08:17

%S 7,11,19,71,79,131,1167,1191,6771,12627,17947,20079,26347,40327,41231,

%T 69379,109587,193559,212451,499391,783831

%N Numbers n such that 73*2^n-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 <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 Kosmaj, <a href="http://www.15k.org/riesellist.html">Riesel list k<300</a>.

%o (PARI) is(n)=ispseudoprime(73*2^n-1) \\ _Charles R Greathouse IV_, Jun 13 2017

%K hard,nonn

%O 1,1

%A _N. J. A. Sloane_, Dec 29 1999

%E More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 02 2008