%I #6 Sep 08 2022 08:46:01
%S 13,229,733,1093,2029,3253,7573,13693,18229,21613,31333,33493,42853,
%T 59053,65029,71293,91813,127453,140629,178933,189229,199813,205213,
%U 227533,233293,245029,257053,328333,378229,439573,514093,567013
%N Primes of the form 9n^2 + 4.
%H Vincenzo Librandi, <a href="/A201706/b201706.txt">Table of n, a(n) for n = 1..5000</a>
%t Select[Table[9n^2+4,{n,0,1000}],PrimeQ]
%o (Magma) [a: n in [0..300] | IsPrime(a) where a is 9*n^2+4];
%K nonn,easy
%O 1,1
%A _Vincenzo Librandi_, Dec 04 2011