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 A139496 #4 Jun 19 2014 15:20:32
%S A139496 31,181,199,229,331,379,421,499,619,631,661,691,709,751,829,859,991,
%T A139496 1021,1039,1171,1279,1291,1321,1489,1549,1609,1621,1699,1741,1831,
%U A139496 1879,1951,2011,2029,2161,2179,2269,2281,2311,2341,2539,2671,2689,2731,2971
%N A139496 Primes of the form x^2 + 13x*y + y^2 for x and y nonnegative.
%H A139496 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 A139496 a = {}; w = 13; 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 A139496 Cf. A139489, A007645, A068228, A007519, A033212, A033212, A107152, A107008, A033215, A107145, A139490, A139491.
%K A139496 nonn
%O A139496 1,1
%A A139496 _Artur Jasinski_, Apr 24 2008