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 A139863 #18 Sep 08 2022 08:45:34
%S A139863 13,23,53,103,127,157,173,263,277,367,373,503,607,647,653,677,727,757,
%T A139863 797,823,887,997,1013,1063,1093,1117,1213,1223,1277,1303,1327,1447,
%U A139863 1453,1543,1583,1613,1637,1663,1693,1733,1823,1847,1933,1973,2053
%N A139863 Primes of the form 10x^2 + 13y^2.
%C A139863 Discriminant = -520. See A139827 for more information.
%H A139863 Vincenzo Librandi and Ray Chandler, <a href="/A139863/b139863.txt">Table of n, a(n) for n = 1..10000</a> [First 1000 terms from Vincenzo Librandi]
%H A139863 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 A139863 The primes are congruent to {13, 23, 53, 77, 87, 103, 127, 133, 157, 173, 183, 207, 237, 263, 277, 287, 303, 367, 373, 407, 413, 477, 493, 503, 517} (mod 520).
%t A139863 QuadPrimes2[10, 0, 13, 10000] (* see A106856 *)
%o A139863 (Magma) [ p: p in PrimesUpTo(3000) | p mod 520 in {13, 23, 53, 77, 87, 103, 127, 133, 157, 173, 183, 207, 237, 263, 277, 287, 303, 367, 373, 407, 413, 477, 493, 503, 517}]; // _Vincenzo Librandi_, Jul 29 2012
%o A139863 (PARI) list(lim)=my(v=List(),w,t); for(x=0, sqrtint(lim\10), w=10*x^2; for(y=1, sqrtint((lim-w)\13), if(isprime(t=w+13*y^2), listput(v,t)))); Set(v) \\ _Charles R Greathouse IV_, Mar 07 2017
%K A139863 nonn,easy
%O A139863 1,1
%A A139863 _T. D. Noe_, May 02 2008