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 A119602 #29 Feb 16 2025 08:33:01 %S A119602 1,1,2,7,39 %N A119602 Number of nonisomorphic polytetrahedra with n identical regular tetrahedra connected face-to-face or edge-to-edge (chiral shapes counted twice). %C A119602 Polytetrahedra are a 3-dimensional generalization of polyiamonds, composed of unit regular tetrahedra in Euclidean 3-space. - _Peter Kagey_, Aug 05 2019, adapted from comment by _Jonathan Vos Post_. %H A119602 Andrew I. Campbell, Valerie J. Anderson, Jeroen S. van Duijneveldt and Paul Bartlett, <a href="https://www.researchgate.net/publication/7670647_Dynamical_Arrest_in_Attractive_Colloids_The_Effect_of_Long-Range_Repulsion">Dynamical Arrest in Attractive Colloids: The Effect of Long-Range Repulsion</a>, Phys. Rev. Lett. 94, 208301 (2005). %H A119602 Peter Kagey, <a href="/A119602/a119602.pdf">Examples of the seven shapes that can be constructed from three tetrahedra</a>, with Mathematica code. %H A119602 J. F. Sadoc, <a href="https://doi.org/10.1007/s100510051009">Boerdijk-Coxeter helix and biological helices</a>, Eur. Phys. J. B 12, 309-318. %H A119602 Jonathan Vos Post, <a href="/A119602/a119602.txt">Original example for entry</a>. %H A119602 Eric Weisstein et al., <a href="https://mathworld.wolfram.com/Tetrahedron.html">Tetrahedron</a>. %H A119602 Wikipedia, <a href="http://en.wikipedia.org/wiki/Polyiamond">Polyiamond</a> %H A119602 Wikipedia, <a href="https://en.wikipedia.org/wiki/Deltahedron">Deltahedron</a> %e A119602 For n = 1, the a(1) = 1 polytetrahedron is the tetrahedron itself. %e A119602 For n = 2, the a(2) = 2 polytetrahedra are formed by either gluing two tetrahedra along a face (triangular bipyramid) or gluing two tetrahedra along an edge. %e A119602 For n = 7, the a(3) = 7 polytetrahedra are given in the links section. %Y A119602 Cf. A000577, A000105. %K A119602 nonn,more %O A119602 0,3 %A A119602 _Jonathan Vos Post_, Jun 02 2006