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 A372733 #8 May 12 2024 10:04:41 %S A372733 12,138,738,2838,7194,17904,33954,62868,103866,167280,248826,370458, %T A372733 511806,715905,952608,1260366 %N A372733 Number of curved edges among all distinct circles that can be constructed from the 3 vertices and the equally spaced 3*n points placed on the sides of an equilateral triangle when every pair of the 3 + 3*n points are connected by a circle and where the points lie at the ends of the circle's diameter. %C A372733 A circle is constructed for every pair of the 3 + 3*n points, the two points lying at the ends of a diameter of the circle. %C A372733 See A372731 and A372732 for images of the circles. %F A372733 a(n) = A372731(n) + A372732(n) - 1 by Euler's formula. %Y A372733 Cf. A372731 (vertices), A372732 (regions), A372734 (k-gons), A372735 (number of circles), A372616, A371375, A356358, A360353. %K A372733 nonn,more %O A372733 0,1 %A A372733 _Scott R. Shannon_, May 12 2024