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 A070205 #13 Jun 19 2025 19:20:46 %S A070205 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0, %T A070205 0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,1, %U A070205 0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,2,0,0,0,0,0,1 %N A070205 Number of acute integer triangles with perimeter n having integral inradius. %D A070205 Mohammad K. Azarian, Circumradius and Inradius, Problem S125, Math Horizons, Vol. 15, Issue 4, April 2008, p. 32. Solution published in Vol. 16, Issue 2, November 2008, p. 32. %H A070205 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Incircle.html">Incircle</a>. %H A070205 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/AcuteTriangle.html">Acute Triangle</a>. %H A070205 R. Zumkeller, <a href="/A070080/a070080.txt">Integer-sided triangles</a> %F A070205 a(n) = A070201(n) - A024155(n) - A070206(n). %Y A070205 Cf. A024155, A070093, A070140, A070201, A070206. %K A070205 nonn %O A070205 1,84 %A A070205 _Reinhard Zumkeller_, May 05 2002