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 A309312 #33 Nov 03 2019 16:44:58 %S A309312 6,30,42,54,66,72,114,132,150,198,204,234,294,306,378,390,408,468,486, %T A309312 522,570,594,648,684,726,744,750,798,816,876,984,1014,1026,1110,1170, %U A309312 1218,1254,1290,1332,1350,1368,1428,1494,1518,1548,1554,1590,1734,1770,1782,1806,1938,1950,1974 %N A309312 Areas of Heronian triangles that uniquely define the lengths of the triangle's sides. %C A309312 These are not necessarily primitive Heronian triangles. The corresponding sequence for primitive Heronian triangles is neither a subset nor a superset of this sequence. %H A309312 Giovanni Resta, <a href="/A309312/b309312.txt">Table of n, a(n) for n = 1..10000</a> (first 500 terms from Jacob Vecht) %H A309312 Wikipedia, <a href="http://en.wikipedia.org/wiki/Heronian_triangle">Heronian triangle</a> %e A309312 A triangle with integer sides and an area of 42 square units necessarily has sides 7,15,20, so 42 is a term. 12 is not a term because an area of 12 could have sides 6,5,5 or 8,5,5. %Y A309312 Subsequence of A188158. %K A309312 nonn,easy %O A309312 1,1 %A A309312 _Jacob Vecht_, Jul 22 2019 %E A309312 Corrected 37th term "1248" to "1254".