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 A091910 #13 Apr 19 2025 19:36:17 %S A091910 1,3,4,10,11,21,20,36,36,55,56,78,79,103,103,136,135 %N A091910 Number of distinct distances between the intersection points in A091908 measured from the center of the equilateral triangle. %H A091910 Hugo Pfoertner, <a href="http://www.randomwalk.de/sequences/a091908.pdf">Visualization of diagonal intersections in an equilateral triangle.</a> %H A091910 Hugo Pfoertner, <a href="http://www.randomwalk.de/sequences/a091908.zip">Diagonal intersections in an equilateral triangle.</a> Program and results. %e A091910 a(2)=1: The 3 line segments intersect each other at the triangle center (r=0). %e A091910 a(3)=3: There are 3 intersection points at r=0.2, 3 at r=0.25 and 6 at r=0.3779645, i.e. 3 different radii. See pictures given at link. %o A091910 (Fortran) ! Program given at link. %Y A091910 Cf. A091908, A092098. %K A091910 more,nonn %O A091910 2,2 %A A091910 _Hugo Pfoertner_, Feb 19 2004