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 A046131 #16 Jul 29 2025 14:51:35
%S A046131 6,24,30,54,24,84,36,60,66,42,96,84,126,90,150,84,120,36,204,210,210,
%T A046131 60,216,132,96,336,72,144,240,294,84,252,360,114,156,180,210,120,210,
%U A046131 420,168,270,264,168,384,240,468,126,180,336,336,504,264,330,486,216
%N A046131 Areas of scalene integer Heronian triangles (A046128, A046129, A046130) sorted by increasing c and b.
%C A046131 This is the ordering of triangles used for A316841.
%H A046131 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/HeronianTriangle.html">Heronian Triangle.</a>
%t A046131 sideMax = 60; r[c_] := Reap[Do[ p = (a + b + c)/2; red = Reduce[ area > 1 && a < b < c && area^2 == p*(p - a)*(p - b)*(p - c), area, Integers]; If[red =!= False, sol = {a, b, c, area} /. {ToRules[red]}; Sow[sol]], {b, 1, c - 1}, {a, c - b, b - 1}]]; triangles = Flatten[ Reap[ Do[rc = r[c]; If[rc[[2]] =!= {}, Sow[rc[[2, 1]]]], {c, 5, sideMax}]][[2, 1]] , 2]; Sort[ triangles, Which[#1[[3]] < #2[[3]], True, #1[[3]] > #2[[3]], False, #1[[2]] < #2[[2]], True, #1[[2]] > #2[[2]], False, #1[[1]] <= #2[[1]], True, True, False] &][[All, 4]] (* _Jean-François Alcover_, Oct 29 2012 *)
%Y A046131 The sides are given by A046128, A046129, A046130.
%Y A046131 Cf. A055595, A072294, A316841, A316853.
%Y A046131 Range of values: A383413.
%K A046131 nonn
%O A046131 0,1
%A A046131 _Eric W. Weisstein_