%I #21 Sep 26 2022 06:18:17

%S 1,2,3,4,5,7,8,9,10,12,14,15,18,19,20,23,25,27,29,30,34,37,38,40,43,

%T 44,45,47,49,52,53,54,55,58,59,63,64,65,67,69,75,82,84,85,88,92,93,95,

%U 99,100,102,113,114,119,124,125,129,130,133,137,139,140,143,144,147,148

%N Numbers k such that k^2 + 3k + 1 is a prime.

%H Zak Seidov, <a href="/A094210/b094210.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = A002328(n)-2. - _R. J. Mathar_, Aug 08 2012

%t Select[ Range[150], PrimeQ[ #^2 + 3# + 1] &] (* _Robert G. Wilson v_, May 29 2004 *)

%o (Magma) [n: n in [0..200] | IsPrime(n^2 + 3*n + 1)]; // _Vincenzo Librandi_, Nov 11 2014

%Y Cf. A002327, A002328, A028387.

%K easy,nonn

%O 1,2

%A _Giovanni Teofilatto_, May 27 2004

%E Edited and extended by _Robert G. Wilson v_, May 29 2004