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 A139984 #16 Sep 08 2022 08:45:34
%S A139984 3,283,307,523,643,787,1123,1483,1627,1867,1987,2203,2467,2707,2803,
%T A139984 3163,3307,3547,3643,4003,4483,4507,4723,4987,5227,5323,5347,5563,
%U A139984 5683,5827,6067,6163,6907,7027,7243,7507,7867,8707,8923,9043,9187
%N A139984 Primes of the form 3x^2+280y^2.
%C A139984 Discriminant=-3360. See A139827 for more information.
%H A139984 Vincenzo Librandi and Ray Chandler, <a href="/A139984/b139984.txt">Table of n, a(n) for n = 1..10000</a> [First 1000 terms from Vincenzo Librandi]
%H A139984 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)
%F A139984 Except for 3, the primes are congruent to {187, 283, 307, 523, 643, 787} (mod 840).
%t A139984 QuadPrimes2[3, 0, 280, 10000] (* see A106856 *)
%o A139984 (Magma) [3] cat [p: p in PrimesUpTo(10000) | p mod 840 in [187, 283, 307, 523, 643, 787]]; // _Vincenzo Librandi_, Aug 03 2012
%K A139984 nonn,easy
%O A139984 1,1
%A A139984 _T. D. Noe_, May 02 2008