%I M3248 #31 Oct 21 2023 01:07:43
%S 1,4,5,10,16,19,20,26,29,31,35,41,44,49,50,55,56,59,70,71,80,85,94,95,
%T 100,101,106,109,110,121,149,154,160,166,175,179,184,190,191,200,205,
%U 206,211,224,236,241,245,251,256,265,269,271,284,286,289,299,304,314
%N Numbers k such that 4*k^2 + 9 is prime.
%D E. Kogbetliantz and A. Krikorian, Handbook of First Complex Prime Numbers, Gordon and Breach, NY, 1971, p. 1.
%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H T. D. Noe, <a href="/A002970/b002970.txt">Table of n, a(n) for n = 1..1000</a>
%H E. Kogbetliantz and A. Krikorian <a href="/A002970/a002970.pdf">Handbook of First Complex Prime Numbers</a>, Gordon and Breach, NY, 1971. [Annotated scans of a few pages]
%t Select[Range[350], PrimeQ[4 #^2 + 9] &] (* _Vincenzo Librandi_, Mar 19 2014 *)
%o (Magma)[n: n in [0..600]|IsPrime(4*n^2+9)]; // _Vincenzo Librandi_, Nov 21 2010
%o (PARI) is(n)=isprime(4*n^2+9) \\ _Charles R Greathouse IV_, Feb 17 2017
%K nonn,easy
%O 1,2
%A _N. J. A. Sloane_