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 A139661 #25 Jan 14 2025 20:51:03
%S A139661 409,433,457,577,769,937,1033,1249,1657,1753,1777,1801,1993,2089,2161,
%T A139661 2473,2593,2617,2857,3001,3217,3313,3433,3673,3697,3793,3889,4129,
%U A139661 4201,4297,4441,4513,4657,5113,5449,5521,5737,5857,5881,6073,6121
%N A139661 Primes of the form x^2 + 408*y^2.
%C A139661 Discriminant = -1632. See A139643 for more information.
%C A139661 The primes are congruent to {1, 25, 49, 121, 145, 169, 217, 361} (mod 408).
%H A139661 Vincenzo Librandi and Ray Chandler, <a href="/A139661/b139661.txt">Table of n, a(n) for n = 1..10000</a> (first 1000 terms from Vincenzo Librandi).
%H A139661 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 A139661 QuadPrimes2[1, 0, 408, 10000] (* see A106856 *)
%o A139661 (Magma) [ p: p in PrimesUpTo(7000) | p mod 408 in {1, 25, 49, 121, 145, 169, 217, 361}]; // _Vincenzo Librandi_, Jul 29 2012
%o A139661 (Magma) k:=408; [p: p in PrimesUpTo(7000) | NormEquation(k, p) eq true]; // _Bruno Berselli_, Jun 01 2016
%K A139661 nonn,easy
%O A139661 1,1
%A A139661 _T. D. Noe_, Apr 29 2008