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 A139503 #4 Jun 19 2014 15:28:56
%S A139503 79,109,151,211,331,379,421,499,541,571,631,709,739,751,919,991,1009,
%T A139503 1051,1129,1171,1201,1381,1429,1471,1549,1579,1621,1759,1789,1801,
%U A139503 1831,1999,2011,2179,2221,2251,2269,2311,2389,2521,2671,2689,2731,2851,3019
%N A139503 Primes of the form x^2 + 23x*y + y^2 for x and y nonnegative.
%H A139503 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 A139503 a = {}; w = 23; k = 1; Do[Do[If[PrimeQ[n^2 + w*n*m + k*m^2], AppendTo[a, n^2 + w*n*m + k*m^2]], {n, m, 400}], {m, 1, 400}]; Union[a] (*Artur Jasinski*)
%Y A139503 Cf. A139489, A007645, A068228, A007519, A033212, A033212, A107152, A107008, A033215, A107145, A139490, A139491.
%K A139503 nonn
%O A139503 1,1
%A A139503 _Artur Jasinski_, Apr 24 2008