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 A081961 #9 Jan 25 2020 15:40:30 %S A081961 5,13,25,41,61,65,85,89,97,113,145,149,157,181,169,185,193,221,205, %T A081961 233,265,269,277,313,289,317,305,365,337,353,377,421,389,425,433,481, %U A081961 425,445,485,461,493,545,481,505,521,557,613,541,569,617,685,689,629,653 %N A081961 Hypotenuses of primitive Pythagorean triangles with an odd short leg (or an even long leg) sorted on semiperimeter. %H A081961 Ray Chandler, <a href="/A081961/b081961.txt">Table of n, a(n) for n = 1..10000</a> %K A081961 nonn %O A081961 1,1 %A A081961 _Lekraj Beedassy_, Apr 23 2003 %E A081961 More terms from _Ray Chandler_, Oct 28 2003