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 A139920 #17 Sep 08 2022 08:45:34
%S A139920 19,59,131,139,251,419,619,691,811,859,971,1091,1259,1291,1459,1531,
%T A139920 1571,1699,1811,1931,1979,2099,2131,2371,2411,2539,2579,2659,2819,
%U A139920 2939,2971,3251,3331,3491,3499,3659,3779,4051,4091,4219,4259,4339
%N A139920 Primes of the form 19x^2+18xy+19y^2.
%C A139920 Discriminant=-1120. See A139827 for more information.
%H A139920 Vincenzo Librandi and Ray Chandler, <a href="/A139920/b139920.txt">Table of n, a(n) for n = 1..10000</a> [First 1000 terms from Vincenzo Librandi]
%H A139920 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 A139920 The primes are congruent to {19, 59, 131, 139, 171, 251} (mod 280).
%t A139920 Union[QuadPrimes2[19, 18, 19, 10000], QuadPrimes2[19, -18, 19, 10000]] (* see A106856 *)
%o A139920 (Magma) [ p: p in PrimesUpTo(6000) | p mod 280 in [19, 59, 131, 139, 171, 251]]; // _Vincenzo Librandi_, Aug 01 2012
%K A139920 nonn,easy
%O A139920 1,1
%A A139920 _T. D. Noe_, May 02 2008