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 A081872 #9 Jan 26 2020 19:59:22 %S A081872 4,12,15,24,21,35,40,45,60,63,56,55,84,77,80,99,72,112,91,117,144,143, %T A081872 105,140,132,180,165,120,176,195,153,168,220,187,156,221,171,255,208, %U A081872 264,209,260,247,252,285,312,231,323,240,308,273,224,364,253,357,288 %N A081872 Long legs of primitive Pythagorean triangles sorted on semiperimeter. %H A081872 Ray Chandler, <a href="/A081872/b081872.txt">Table of n, a(n) for n = 1..10000</a> %Y A081872 Cf. A020886, A020883, A046087. %K A081872 nonn %O A081872 1,1 %A A081872 _Lekraj Beedassy_, Apr 23 2003 %E A081872 More terms from _Ray Chandler_, Oct 29 2003