This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A139666 #21 Sep 08 2022 08:45:33
%S A139666 1321,1489,1609,2161,2281,2689,3001,3169,3529,4129,4801,5281,5449,
%T A139666 5569,5641,6121,6361,6961,7129,7489,7561,7681,8089,8209,8761,9001,
%U A139666 9241,9601,9769,10321,10729,12049,12241,12409,12721,12841,13249,13729
%N A139666 Primes of the form x^2 + 1320*y^2.
%C A139666 Discriminant = -5280. See A139643 for more information.
%C A139666 The primes are congruent to {1, 49, 169, 289, 361, 529, 841, 889, 961, 1081} (mod 1320).
%H A139666 Vincenzo Librandi and Ray Chandler, <a href="/A139666/b139666.txt">Table of n, a(n) for n = 1..10000</a> (first 1000 terms from Vincenzo Librandi).
%H A139666 N. J. A. Sloane et al., <a href="https://oeis.org/wiki/Binary_Quadratic_Forms_and_OEIS">Binary Quadratic Forms and OEIS</a> (Index to related sequences, programs, references)
%t A139666 QuadPrimes2[1, 0, 1320, 10000] (* see A106856 *)
%o A139666 (Magma) [ p: p in PrimesUpTo(15000) | p mod 1320 in {1, 49, 169, 289, 361, 529, 841, 889, 961, 1081}]; // _Vincenzo Librandi_, Jul 29 2012
%o A139666 (Magma) k:=1320; [p: p in PrimesUpTo(14000) | NormEquation(k, p) eq true]; // _Bruno Berselli_, Jun 01 2016
%K A139666 nonn,easy
%O A139666 1,1
%A A139666 _T. D. Noe_, Apr 29 2008