%I #38 Feb 05 2024 00:54:38
%S 1,3,4,6,9,10,13,16,19,21,24,25,28,30,33,34,39,45,46,48,54,55,58,60,
%T 61,63,75,76,79,81,90,91,93,94,103,105,108,111,114,115,121,123,124,
%U 129,130,133,136,138,144,153,154,160,163,165,166,171,175,178,180
%N Numbers k such that 8k - 1 is prime.
%C Corresponding primes are listed in A007522. - _Altug Alkan_, Dec 10 2015
%H Harvey P. Dale, <a href="/A005122/b005122.txt">Table of n, a(n) for n = 1..1000</a>
%p A005122:=n->`if`(isprime(8*n-1), n, NULL): seq(A005122(n), n=1..300); # _Wesley Ivan Hurt_, Dec 11 2015
%t Select[Range[160], PrimeQ[8#-1]&] (* _Harvey P. Dale_, Nov 25 2011 *)
%o (PARI) isok(n) = isprime(8*n-1); \\ _Michel Marcus_, Dec 10 2015
%o (Magma) [n: n in [1..200] | IsPrime(8*n-1)]; // _Vincenzo Librandi_, Dec 10 2015
%Y Cf. A007522.
%K nonn,easy
%O 1,2
%A _N. J. A. Sloane_