A155771 - OEIS

%I #9 Sep 08 2022 08:45:41

%S 5,6,7,8,9,10,11,12,14,15,16,17,18,19,21,22,23,25,27,28,29,33,34,39,

%T 42,44,45,46,48,50,52,53,56,57,58,59,61,65,66,68,69,74,77,80,83,86,87,

%U 90,91,93,95,96,99,101,103,104,106,107,110,116,121,126,128,130,131,133,136

%N Numbers n such that 2*n^2+2*n-41 is a prime.

%H Vincenzo Librandi, <a href="/A155771/b155771.txt">Table of n, a(n) for n = 1..1000</a>

%e For n=14, a(14)=379; n=140, a(140)=39439.

%t Select[Range[4, 200], PrimeQ[2#^2+2#-41]&] (* _Vincenzo Librandi_, Sep 24 2012 *)

%o (Magma) [n: n in [4..150] | IsPrime(2*n^2+2*n-41)]; // _Vincenzo Librandi_, Sep 24 2012

%Y Cf. A155769, A155770, A155772.

%K nonn,easy

%O 1,1

%A _Vincenzo Librandi_, Jan 27 2009