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 A344896 #26 Jul 21 2021 09:09:45 %S A344896 3,21,186,705,2196,5046,10212,19149,31524,50049,77100,114633,159453, %T A344896 225978,298833,390069,508137,663426,824868,1040727,1258833,1532565, %U A344896 1859331,2254938,2628309,3130227,3664920,4261503,4917939,5742696,6503331,7511280,8507322,9658806,10855989,12237066 %N A344896 Number of polygon edges formed by infinite lines when connecting all vertices and all points that divide the sides of an equilateral triangle into n equal parts. %C A344896 See A344279 for images of the polygons. %F A344896 a(n) = A344279(n) + A344657(n) - 1. %Y A344896 Cf. A344279 (number of polygons), A344657 (number of vertices), A346446 (number of k-gons), A092867 (number polygons inside the triangle), A344899, A345650. %K A344896 nonn %O A344896 1,1 %A A344896 _Scott R. Shannon_, Jun 24 2021