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 A054909 #24 Jan 25 2025 09:14:51 %S A054909 1,1,2,24 %N A054909 Number of 8n-dimensional even unimodular lattices (or quadratic forms). %C A054909 King shows that a(4) >= 1162109024. - _Charles R Greathouse IV_, Nov 05 2013 %D A054909 J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 49. %H A054909 Steven R. Finch, <a href="http://www.people.fas.harvard.edu/~sfinch/">Minkowski-Siegel mass constants</a> [Broken link] %H A054909 Steven R. Finch, <a href="https://oeis.org/A241121/a241121.pdf">Minkowski-Siegel mass constants</a> %H A054909 Oliver King, <a href="http://arxiv.org/abs/math/0012231">A mass formula for unimodular lattices with no roots</a>, arXiv:math/0012231 [math.NT], 2000-2001; Mathematics of Computation 72:242 (2003), pp. 839-863. %F A054909 a(n) = A005134(8*n) - A054911(8*n). - _Robin Visser_, Jan 24 2025 %Y A054909 Cf. A005134, A054907, A054908, A054911. %K A054909 nonn,nice,hard %O A054909 0,3 %A A054909 _N. J. A. Sloane_, May 23 2000 %E A054909 The classical mass formula shows that the next term is at least 8*10^7. %E A054909 Oliver King and Richard Borcherds (reb(AT)math.berkeley.edu) have recently improved this estimate and have shown that a(4), the number in dimension 32, is at least 10^9 (Jul 22 2000)