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%I #22 Sep 18 2024 11:49:02
%S 2,3,5,9,12,14,20,21,23,26,27,30,32,33,35,38,41,44,47,51,53,59,60,65,
%T 66,68,69,74,80,81,86,87,90,93,95,104,107,108,111,114,117,119,122,126,
%U 131,137,140,143,150,152,153,156,159,161,165,168,173,177,179,185,188,191
%N Numbers k such that 20*k + 1 is prime.
%e If k=95 then 20*k + 1 = 1901 (prime).
%o (Magma) [n: n in [0..6000] | IsPrime(20*n + 1)]; // _Vincenzo Librandi_, Mar 26 2010
%o (PARI) is(n)=isprime(20*n+1) \\ _Charles R Greathouse IV_, Jun 13 2017
%K nonn,easy
%O 1,1
%A _Parthasarathy Nambi_, Dec 07 2006