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%I #26 Sep 08 2022 08:45:00
%S 2,4,16,58,70,80,158,202,322,356,616,2152,3136,3308,3626,5930,6046,
%T 8930,9100,10046,10142,16696,17996,23318,25900,39934,63794,69260,
%U 300632,302248,307132,311924,451724,1155950,1639448,1745450
%N Numbers k such that 265*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 <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[5*10^3], PrimeQ[265*2^# + 1] &] (* _G. C. Greubel_, May 24 2018 *)
%o (PARI) is(n)=ispseudoprime(265*2^n+1) \\ _Charles R Greathouse IV_, Jun 13 2017
%o (Magma) [n: n in [1..300] | IsPrime(265*2^n+1)]; // _G. C. Greubel_, May 24 2018
%K hard,nonn,more
%O 1,1
%A _N. J. A. Sloane_, Dec 29 1999
%E a(29)-a(36) from the Ray Ballinger and Wilfrid Keller link by _Robert Price_, Dec 20 2018