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 A081977 #10 Jan 25 2020 22:27:02 %S A081977 15,21,35,45,63,55,77,99,91,117,143,105,165,195,153,187,221,171,255, %T A081977 209,247,285,231,323,273,253,357,299,399,345,275,391,325,437,483,425, %U A081977 351,475,525,459,575,377,513,435,493,621,403,551,675,465,609,527,667,589 %N A081977 Odd long legs of primitive Pythagorean triangles sorted on semiperimeter. %H A081977 Ray Chandler, <a href="/A081977/b081977.txt">Table of n, a(n) for n = 1..10000</a> %K A081977 nonn %O A081977 1,1 %A A081977 _Lekraj Beedassy_, Apr 23 2003 %E A081977 More terms from _Ray Chandler_, Oct 29 2003