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 A364109 #10 Jul 05 2023 15:03:56 %S A364109 4,1,9,36,1,1,3,49,17689,4900,2,81,8,1764,289,12,16,49,2289169, %T A364109 1158313156,44,10227204,22801,4,169,2,121,2809,1,166952241,36,49,169, %U A364109 75,529,76,3975302500,1,7551929273974569,1764,1,12,19298449,25,305111826865145547009,143811,14161,3136,1,1 %N A364109 a(n) is the lesser coefficient of the pair (x, y) such that (x^2-y^2)/r, 2*x*y/r, (x^2+y^2)/r are the 2 legs and hypotenuse of the least Pythagorean triple having area A006991(n). %H A364109 Michel Marcus, <a href="/A364109/b364109.txt">Table of n, a(n) for n = 1..361</a> %H A364109 Mauro Fiorentini, <a href="http://bitman.name/math/table/29">Numeri congruenti minori di 1000</a>. See column b. %H A364109 David Goldberg, <a href="https://arxiv.org/abs/2106.07373">Triangle Sides for Congruent Numbers less than 10,000</a>, arXiv:2106.07373 [math.NT], 2021. See column Q, p. 7. %H A364109 Hisanori Mishima, <a href="http://www.asahi-net.or.jp/~KC2H-MSM/mathland/math10/matb2000.htm">Congruum</a>. See column n. %Y A364109 Cf. A006991 (primitive congruent numbers), A364108 (x), A364110 (r). %K A364109 nonn %O A364109 1,1 %A A364109 _Michel Marcus_, Jul 05 2023