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 A330584 #16 Jun 14 2024 22:31:10 %S A330584 60,168,360,504,660,1092,2448,2520,3420,4080,5616,6048,6072,7800,7920, %T A330584 20160,20160,25920,62400,95040,126000,181440,443520,604800,979200, %U A330584 1451520,1814400,3265920,4245696,10200960 %N A330584 The orders, with repetition, of the non-cyclic finite simple groups that are subquotients of the automorphism groups of sublattices of the Leech lattice. %C A330584 Note: not every sublattice of the Leech lattice is necessarily a section of the Leech lattice. For example, every Niemeyer lattice is commensurable with the Leech lattice; thus the orders of the simple components of their automorphism groups are in this list, even when those groups are not sections of Co0. %C A330584 By a theorem of Conway and Sloane, any simple group with a cover that has a crystallographic representation in <= 21 dimensions is in this list. %C A330584 This is a subsequence of A330583. %D A330584 J. H. Conway, R. T. Curtis, S. P. Norton, R. A. Parker and R. A. Wilson, ATLAS of Finite Groups. Oxford Univ. Press, 1985 [for best online version see https://oeis.org/wiki/Welcome#Links_to_Other_Sites]. %D A330584 J. H. Conway, N. J. A. Sloane, Sphere Packings, Lattices, and Groups. Springer, 3rd ed., 1999. %H A330584 Hal M. Switkay, <a href="/A330584/b330584.txt">Table of n, a(n) for n = 1..56</a> %H A330584 J. H. Conway, N. J. A. Sloane, <a href="https://doi.org/10.1098/rspa.1989.0124">Low-dimensional lattices V: Integral coordinates for integral lattices</a>, Proc. Royal Soc. A 426 (1989), 211-232. %H A330584 David A. Madore, <a href="http://www.madore.org/~david/math/simplegroups.html">Orders of non-abelian simple groups</a> %H A330584 R. A. Wilson et al., <a href="http://brauer.maths.qmul.ac.uk/Atlas/v3/">ATLAS of Finite Group Representations - Version 3</a> %e A330584 All simple groups of order less than 9828 have crystallographic representations within sublattices of the Leech lattice. The smallest nontrivial crystallographic representation of L2(27), of order 9828, is 26-dimensional. %Y A330584 Cf. A109379, A080683, A330583. %K A330584 nonn,fini,full %O A330584 1,1 %A A330584 _Hal M. Switkay_, Dec 18 2019