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 A081874 #15 Jan 21 2020 13:52:20
%S A081874 3,5,7,9,11,13,15,17,19,21,23,25,27,29,31,33,33,35,37,39,39,41,43,45,
%T A081874 47,49,51,51,53,55,57,57,59,61,63,65,65,67,69,69,71,73,75,75,77,79,81,
%U A081874 83,85,85,87,87,89,91,93,93,95,95,97,99,101,103,105,105,105,107,109,111
%N A081874 Ordered odd short legs of primitive Pythagorean triangles.
%C A081874 Sequence comprises all odd values greater than 1. In particular, primitive Pythagorean triangles with consecutive longer sides have long and short legs 2n(n+1) {A046092(n)} and 2n+1 {A005408(n)} respectively.
%H A081874 Ray Chandler, <a href="/A081874/b081874.txt">Table of n, a(n) for n = 1..10000</a>
%H A081874 Ron Knott, <a href="http://www.maths.surrey.ac.uk/hosted-sites/R.Knott/Pythag/pythag.html">Pythagorean Triples and Online Calculators</a>
%Y A081874 Cf. A020884, A046092, A005408.
%K A081874 nonn
%O A081874 1,1
%A A081874 _Lekraj Beedassy_, Apr 23 2003
%E A081874 Corrected and extended by _Ray Chandler_, Oct 29 2003