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 A330174 #18 Feb 20 2020 10:02:39
%S A330174 0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,
%T A330174 0,0,0,0,0,0,1,0,0,0,0,0,1,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
%U A330174 0,0,1,0,1,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,2
%N A330174 Number of primitive Pythagorean triangles with sum of legs n.
%H A330174 Ray Chandler, <a href="/A330174/b330174.txt">Table of n, a(n) for n = 1..10000</a>
%t A330174 f[n_]:=Block[{ps,sps}, ps=First/@FactorInteger[n];
%t A330174 sps=Select[ps,MemberQ[{1,7},Mod[#,8]]&];
%t A330174 If[sps==ps&&n!=1,2^(Length[ps]-1),0]]; Table[f[n],{n,120}]
%Y A330174 Cf. A058529, A198441.
%K A330174 nonn
%O A330174 1,119
%A A330174 _Ray Chandler_, Feb 15 2020