%I #20 Jul 09 2023 10:05:16

%S 0,1,2,3,4,6,9,11,12,14,16,17,18,21,22,23,24,26,28,29,31,34,37,38,43,

%T 47,49,54,56,57,58,62,64,66,67,68,69,79,81,82,83,84,86,87,88,93,97,

%U 102,104,106,109,113,114,116,117,119,121,123,126,128,131,133,136,138,139,141

%N Numbers k such that 42k + 5 is prime.

%H Ivan Neretin, <a href="/A163627/b163627.txt">Table of n, a(n) for n = 1..10000</a>

%H Dario Alpern, <a href="https://www.alpertron.com.ar/ECM.HTM">Factorization using the Elliptic Curve Method</a>

%e If n = 97 then 42n + 5 = 4079 (a prime).

%t Select[Range[0, 150], PrimeQ[42 # + 5] &] (* _Ivan Neretin_, Nov 26 2016 *)

%o (Magma) [n: n in [0..1000] |IsPrime(42*n + 5)] // _Vincenzo Librandi_, Dec 02 2010

%o (PARI) is(n)=isprime(42*n+5) \\ _Charles R Greathouse IV_, Jun 13 2017

%K nonn,easy

%O 1,3

%A _Parthasarathy Nambi_, Aug 01 2009

%E More terms from _Vincenzo Librandi_, Mar 25 2010