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 A097700 #9 Sep 08 2022 08:45:14
%S A097700 5,7,10,13,14,15,20,21,23,26,28,29,30,31,35,37,39,40,42,45,46,47,52,
%T A097700 53,55,56,58,60,61,62,63,65,69,70,71,74,77,78,79,80,84,85,87,90,91,92,
%U A097700 93,94,95,101,103,104,105,106,109,110,111,112,115,116,117,119,120,122
%N A097700 Numbers not of form x^2 + 2y^2.
%C A097700 Is lim_{n->inf} a(n)/n = 3/4?
%H A097700 Vincenzo Librandi, <a href="/A097700/b097700.txt">Table of n, a(n) for n = 1..6800</a>
%t A097700 formQ[n_]:=Reduce[x>=0&&y>=0&&n==x^2 + 2 y^2, {x, y}, Integers]==False; Select[Range[0, 200], formQ] (* _Vincenzo Librandi_, Jan 15 2017 *)
%o A097700 (Magma) [n: n in [0..160] | NormEquation(2, n) eq false]; // _Vincenzo Librandi_, Jan 15 2017
%Y A097700 Complement of A002479.
%K A097700 nonn
%O A097700 1,1
%A A097700 _Ralf Stephan_, Aug 23 2004