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 A139500 #6 Nov 02 2022 12:55:18
%S A139500 97,157,229,577,661,709,829,1453,1549,1609,1621,1873,2017,2137,2473,
%T A139500 2677,2689,2797,2953,3001,3037,3217,3301,3433,3457,3613,3733,4093,
%U A139500 4261,4273,4357,4513,4621,4657,4801,4933,5113,5281,5437,5641,6229,6301,6337
%N A139500 Primes of the form x^2 + 20x*y + y^2 for x and y nonnegative.
%H A139500 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 A139500 a = {}; w = 20; 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*)
%t A139500 With[{nn=50},Take[Select[Union[Flatten[Table[x^2+20 x y +y^2,{x,0,2nn},{y,0,2nn}]]],PrimeQ],nn]] (* _Harvey P. Dale_, Nov 02 2022 *)
%Y A139500 Cf. A139489, A007645, A068228, A007519, A033212, A033212, A107152, A107008, A033215, A107145, A139490, A139491.
%K A139500 nonn
%O A139500 1,1
%A A139500 _Artur Jasinski_, Apr 24 2008