A032459 - OEIS

%I #35 Dec 23 2024 12:14:33

%S 1,2,3,5,7,9,12,17,25,33,39,43,51,65,71,72,84,100,104,168,198,264,282,

%T 293,352,379,611,676,719,729,745,1013,1407,1417,1532,1887,1902,1993,

%U 2137,2294,2381,2509,3259,4224,4713,5719,6613,7515,8575,8935,11598,12500

%N Numbers k such that 165*2^k+1 is prime.

%H Jeppe Stig Nielsen, <a href="/A032459/b032459.txt">Table of n, a(n) for n = 1..110</a> (terms n = 1..101 from Robert Price)

%H Ray Ballinger, <a href="http://www.prothsearch.com/index.html">Proth Search Page</a>.

%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>.

%t Select[Range[1000], PrimeQ[165*2^# + 1] & ] (* _Robert Price_, Dec 18 2018 *)

%o (PARI) is(n)=ispseudoprime(165*2^n+1) \\ _Charles R Greathouse IV_, Jun 13 2017

%K nonn,hard

%O 1,2

%A _N. J. A. Sloane_

%E a(52)-a(101) from the Ray Ballinger and Wilfrid Keller link by _Robert Price_, Dec 18 2018