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Numbers k such that 111*2^k-1 is prime.
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%I #20 Dec 31 2023 17:45:42

%S 2,3,6,7,21,22,23,26,29,31,58,59,67,78,83,146,159,162,165,183,262,511,

%T 718,815,1181,1255,1422,1506,1541,1734,2213,3623,4223,4551,5741,5878,

%U 6599,11349,12102,17811,19798,20559,26887,32499,40626,43151,49194,52859,98462,101962,126754,133062,147346,217034,279227,345867,362466,378595,448102,520923,602565,656935,791502

%N Numbers k such that 111*2^k-1 is prime.

%C Also in the sequence: 959671. - Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 02 2008

%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(111*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