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 A139976 #17 Sep 08 2022 08:45:34
%S A139976 23,103,127,263,367,503,607,647,727,823,887,1063,1223,1303,1327,1447,
%T A139976 1543,1583,1663,1823,1847,2063,2207,2287,2383,2447,2687,2887,2903,
%U A139976 3407,3527,3623,3727,3767,3823,3847,3943,4007,4423,4447,4463,4567
%N A139976 Primes of the form 23x^2+6xy+23y^2.
%C A139976 Discriminant=-2080. See A139827 for more information.
%H A139976 Vincenzo Librandi and Ray Chandler, <a href="/A139976/b139976.txt">Table of n, a(n) for n = 1..10000</a> [First 1000 terms from Vincenzo Librandi]
%H A139976 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 A139976 The primes are congruent to {23, 87, 103, 127, 183, 207, 263, 287, 303, 367, 407, 503} (mod 520).
%t A139976 Union[QuadPrimes2[23, 6, 23, 10000], QuadPrimes2[23, -6, 23, 10000]] (* see A106856 *)
%o A139976 (Magma) [p: p in PrimesUpTo(6000) | p mod 520 in [23, 87, 103, 127, 183, 207, 263, 287, 303, 367, 407, 503]]; // _Vincenzo Librandi_, Aug 03 2012
%K A139976 nonn,easy
%O A139976 1,1
%A A139976 _T. D. Noe_, May 02 2008