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 A332376 #13 Feb 13 2020 15:26:31 %S A332376 3,12,39,54,123,144,255,282,435,468,663,702,939,984,1245,1314,1635, %T A332376 1692,2055,2100,2523,2592,3039,3042,3603,3684,4215,4302,4875,4950, %U A332376 5583,5682,6339,6444,7107,7254,7995,8112,8895,8964,9843,9936,10839,10974 %N A332376 Total number of edges in graph formed by the straight line segments connecting the edges of an equilateral triangle with the n-1 points resulting from a subdivision of the sides into n equal pieces. %H A332376 N. J. A. Sloane, <a href="/A332376/b332376.txt">Table of n, a(n) for n = 1..1000</a> %F A332376 a(n) = A092098(n) + A331782(n) - 1 (Euler's formula). %Y A332376 Cf. A091908, A092098 (number of cells), A331782 (number of vertices). %Y A332376 Equals three times A332377. %K A332376 nonn %O A332376 1,1 %A A332376 _N. J. A. Sloane_, Feb 13 2020