%I #11 Jun 12 2017 19:22:16
%S 6,18,36,42,84,102,108,132,144,150,162,168,174,186,192,246,276,288,
%T 300,312,330,354,372,384,396,402,456,462,498,510,522,528,552,564,570,
%U 582,612,636,648,708,738,804,816,834,840,846,882,888,924,930,942,972,990
%N Numbers n such that 5*n^2 + 1 is prime.
%H Harvey P. Dale, <a href="/A111147/b111147.txt">Table of n, a(n) for n = 1..1000</a>
%e If n=312 then 5*n^2 + 1 = 486721 (prime).
%t Select[Range[1000], PrimeQ[5*#^2 + 1] &] (* _Stefan Steinerberger_, Feb 26 2006 *)
%o (PARI) is(n)=isprime(5*n^2+1) \\ _Charles R Greathouse IV_, Jun 12 2017
%K nonn,easy
%O 1,1
%A _Parthasarathy Nambi_, Oct 18 2005
%E More terms from _Stefan Steinerberger_, Feb 26 2006