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 A070140 #7 Feb 16 2025 08:32:46 %S A070140 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0, %T A070140 0,1,0,0,0,0,0,1,0,0,0,0,0,1,0,1,0,0,0,1,0,0,0,0,0,0,0,0,0,2,0,0,0,1, %U A070140 0,1,0,1,0,0,0,0,0,0,0,1,0,0,0,2,0,0,0,0,0,1 %N A070140 Number of acute integer triangles with perimeter n having integral area. %C A070140 a(n) = A051516(n) - A070141(n) - A024155(n). %H A070140 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/HeronianTriangle.html">Heronian Triangle</a>. %H A070140 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/AcuteTriangle.html">Acute Triangle</a>. %H A070140 R. Zumkeller, <a href="/A070080/a070080.txt">Integer-sided triangles</a> %Y A070140 Cf. A051516, A070093, A070146. %K A070140 nonn %O A070140 1,64 %A A070140 _Reinhard Zumkeller_, May 05 2002