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 A342353 #14 Mar 17 2021 23:33:15
%S A342353 0,8,80,416,1512,4216,10000,21256
%N A342353 Number of ways to choose 3 points that form an equilateral triangle from the A001845(n) points in a regular octahedral grid of size n.
%C A342353 The octahedral grid of side length n is the set of points (x,y,z) in Z^3 such that |x|+|y|+|z| <= n. The number of points in this grid is given by A001845(n).
%e A342353 For n = 1, the a(1) = 8 equilateral triangles are given by the convex hulls of {(+-1,0,0),(0,+-1,0),(0,0,+-1)}.
%Y A342353 Cf. A001845.
%Y A342353 Cf. A102698 and A334581 are analogous for the cubic grid and tetrahedral grid respectively.
%K A342353 nonn,more
%O A342353 0,2
%A A342353 _Peter Kagey_, Mar 08 2021