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 A334791 #12 Jun 16 2020 14:44:07
%S A334791 12,30,70,84,132,182,260,340,374,390,420,462,476,494,510,598,646,782,
%T A334791 798,870,966,1012,1054,1254,1276,1302,1334,1508,1518,1612,1628,1716,
%U A334791 1804,1860,1892,1924,2030,2046,2132,2220,2262,2310,2380,2444,2460,2494,2516,2542
%N A334791 Perimeters of Pythagorean triangles with squarefree area.
%C A334791 The smallest terms corresponding to 2, 3, and 4 triangles are a(32) = 1716, a(1325) = 81510, and a(5027) = 317460, respectively. - _Giovanni Resta_, May 11 2020
%H A334791 Giovanni Resta, <a href="/A334791/b334791.txt">Table of n, a(n) for n = 1..10000</a>
%H A334791 Wikipedia, <a href="https://en.wikipedia.org/wiki/Integer_triangle">Integer Triangle</a>
%H A334791 <a href="/index/Ps#PyTrip">Index entries related to Pythagorean Triples.</a>
%e A334791 a(1) = 12; There is one Pythagorean triangle, [3,4,5], with perimeter 12 whose area 3*4/2 = 6 (squarefree).
%t A334791 Reap[ Do[s = Solve[ x^2 + y^2 == (p-x-y)^2 && 0<x<y && p-x-y > 0, {x, y}, Integers]; If[s != {} && AnyTrue[x y/2 /. s, SquareFreeQ], Print@ Sow@ p], {p, 12, 1000, 2}]][[2, 1]] (* _Giovanni Resta_, May 11 2020 *)
%Y A334791 Cf. A010814.
%K A334791 nonn
%O A334791 1,1
%A A334791 _Wesley Ivan Hurt_, May 10 2020
%E A334791 Terms a(39) and beyond from _Giovanni Resta_, May 11 2020