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 A308222 #20 Aug 12 2022 09:19:13 %S A308222 16,18,36,50,64,98,100,144,162,196,242,256,324,338,400,450,484,576, %T A308222 578,676,722,784,882,900,1024,1058,1156,1250,1296,1444,1458,1600,1682, %U A308222 1764,1922,1936,2116,2178,2304,2450,2500,2704,2738,2916,3042,3136 %N A308222 Numbers that are the perimeter of a primitive Heronian isosceles triangle. %C A308222 A primitive Heronian triangle is a triangle with integer sides and area, where the side lengths do not share a common divisor. %H A308222 Mathematics Stack Exchange user "George", <a href="https://math.stackexchange.com/a/3230072/121988">Semiperimeter of isosceles Heronian triangles</a>. %H A308222 Wikipedia, <a href="https://en.wikipedia.org/wiki/Integer_triangle#Isosceles_Heronian_triangles">Isosceles Heronian triangles</a>. %F A308222 a(n) = 2*A096033(n+2) (conjectured). %e A308222 Table illustrating first six terms of the sequence: %e A308222 perimeter | sides | area %e A308222 ----------+------------+----- %e A308222 16 | (5,5,6) | 12 %e A308222 18 | (5,5,8) | 12 %e A308222 36 | (10,13,13) | 60 %e A308222 50 | (13,13,24) | 60 %e A308222 50 | (16,17,17) | 120 %e A308222 64 | (14,25,25) | 168 %e A308222 64 | (17,17,30) | 120 %e A308222 98 | (24,37,37) | 420 %e A308222 98 | (25,25,48) | 168 %e A308222 98 | (29,29,40) | 420 %Y A308222 Cf. A046790, A096033, A096468. %K A308222 nonn %O A308222 1,1 %A A308222 _Peter Kagey_, May 16 2019