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 A070206 #13 Feb 16 2025 08:32:46 %S A070206 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, %T A070206 0,1,0,0,0,0,0,1,0,1,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,1,0,0,0,1,0,1,0,0, %U A070206 0,0,0,1,0,0,0,1,0,1,0,1,0,0,0,4,0,0,0,1,0,0 %N A070206 Number of obtuse integer triangles with perimeter n having integral inradius. %C A070206 a(n) = A070201(n) - A024155(n) - A070205(n). %D A070206 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 A070206 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Incircle.html">Incircle</a>. %H A070206 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/ObtuseTriangle.html">Obtuse Triangle</a>. %H A070206 R. Zumkeller, <a href="/A070080/a070080.txt">Integer-sided triangles</a> %Y A070206 Cf. A070141, A070101. %K A070206 nonn %O A070206 1,84 %A A070206 _Reinhard Zumkeller_, May 05 2002