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 A139508 #8 Jun 19 2014 15:30:30
%S A139508 61,181,601,829,1069,1249,1381,1429,1609,1621,1741,2029,2089,2161,
%T A139508 2341,2389,2521,3121,3169,3181,3301,3709,3769,4021,4261,4549,4729,
%U A139508 4801,4861,4969,5209,5281,5521,5581,5641,5749,5821,6301,6361,6421,6529,6709,6829
%N A139508 Primes of the form x^2 + 28x*y + y^2 for x and y nonnegative.
%C A139508 In base 12, the sequence is 51, 131, 421, 591, 751, 881, 971, 9E1, E21, E31, 1011, 1211, 1261, 1301, 1431, 1471, 1561, 1981, 1X01, 1X11, 1XE1, 2191, 2221, 23E1, 2571, 2771, 28X1, 2941, 2991, 2X61, 3021, 3081, 3241, 3291, 3321, 33E1, 3451, 3791, 3821, 3871, 3941, 3X71, 3E51, where X is 10 and E is 11. Moreover, the discriminant is 550. - _Walter Kehowski_, Jun 01 2008
%H A139508 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 A139508 a = {}; w = 28; 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 A139508 Cf. A139489, A007645, A068228, A007519, A033212, A033212, A107152, A107008, A033215, A107145, A139490, A139491.
%K A139508 nonn
%O A139508 1,1
%A A139508 _Artur Jasinski_, Apr 24 2008