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 A070106 #7 May 12 2018 10:05:30 %S A070106 0,0,0,0,0,0,1,0,0,0,1,0,0,1,1,0,0,1,1,0,1,1,1,1,1,1,1,1,1,1,2,1,1,1, %T A070106 2,1,1,2,2,1,2,2,2,1,2,2,2,2,2,2,2,2,2,2,3,2,2,2,3,2,2,3,3,2,3,3,3,2, %U A070106 3,3,3,3,3,3,3,3,3,3,4,3,3,4,4,3,3,4,4,3,4,4 %N A070106 Number of integer triangles with perimeter n which are obtuse and isosceles. %C A070106 a(n)=A070101(n)-A024156(n); a(n)=A059169(n)-A070098(n). %H A070106 R. Zumkeller, <a href="/A070080/a070080.txt">Integer-sided triangles</a> %e A070106 For n=11 there are A005044(11)=4 integer triangles: [1,5,5], [2,4,5], [3,3,5] and [3,4,4]; only one of the two obtuses ([2,4,5] and [3,3,5]) is also isosceles; therefore a(11)=1. %Y A070106 Cf. A070080, A070081, A070082, A059169, A070107, A070108, A070133. %K A070106 nonn %O A070106 1,31 %A A070106 _Reinhard Zumkeller_, May 05 2002