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 A139658 #22 Sep 08 2022 08:45:33
%S A139658 349,409,541,601,829,1021,1129,1381,1429,1549,1669,1741,1789,2221,
%T A139658 2281,2341,2749,3049,3061,3109,3121,3169,3229,3301,3361,3709,3889,
%U A139658 4129,4261,4441,4549,4861,4969,5101,5521,5569,5641,5689,5821,5869
%N A139658 Primes of the form x^2 + 345*y^2.
%C A139658 Discriminant = -1380. See A139643 for more information.
%C A139658 The primes are congruent to {1, 49, 121, 169, 289, 301, 349, 361, 409, 469, 541, 601, 721, 829, 841, 901, 949, 961, 1021, 1129, 1189, 1369} (mod 1380).
%H A139658 Vincenzo Librandi and Ray Chandler, <a href="/A139658/b139658.txt">Table of n, a(n) for n = 1..10000</a> (first 1000 terms from Vincenzo Librandi).
%H A139658 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 A139658 QuadPrimes2[1, 0, 345, 10000] (* see A106856 *)
%o A139658 (Magma) [ p: p in PrimesUpTo(7000) | p mod 1380 in {1, 49, 121, 169, 289, 301, 349, 361, 409, 469, 541, 601, 721, 829, 841, 901, 949, 961, 1021, 1129, 1189, 1369}]; // _Vincenzo Librandi_, Jul 29 2012
%o A139658 (Magma) k:=345; [p: p in PrimesUpTo(6000) | NormEquation(k, p) eq true]; // _Bruno Berselli_, Jun 01 2016
%K A139658 nonn,easy
%O A139658 1,1
%A A139658 _T. D. Noe_, Apr 29 2008