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 A331140 #13 Jan 25 2022 09:28:04 %S A331140 1,1,16,0,36,16,64,0,152,36,144,0,196,64,576,0,324,152,400,0,1024,144, %T A331140 576,0,912,196,1392,0,900,576,1024,0,2304,324,2304,0,1444,400,3136,0, %U A331140 1764,1024,1936,0,5472,576,2304,0,3152,912,5184,0,2916,1392,5184,0 %N A331140 Number of different coincidence site lattices of index n in lattice Z^4. %H A331140 Michael Baake and Peter Zeiner, <a href="https://doi.org/10.1080/14786430701846206">Coincidences in 4 dimensions</a>, Phil. Mag. 88 (2008), 2025-2032; arXiv:<a href="https://arxiv.org/abs/0712.0363">0712.0363</a> [math.MG]. See end of Section 2.2. %F A331140 a(2k-1) = a(4k-2) = A331139(k), a(4k) = 0. - _Andrey Zabolotskiy_, Jan 29 2020 %Y A331140 Cf. A031361, A331139, A331141, A331142. %K A331140 nonn,mult %O A331140 1,3 %A A331140 _N. J. A. Sloane_, Jan 12 2020 %E A331140 Name corrected, a(2) corrected, and terms a(18) and beyond added by _Andrey Zabolotskiy_, Jan 29 2020