%I #14 Apr 19 2019 02:58:02
%S 1,1,2,24
%N Number of 8n-dimensional even unimodular lattice (or quadratic forms).
%C King shows that a(4) >= 1162109024. - _Charles R Greathouse IV_, Nov 05 2013
%D J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 49.
%H Oliver King, <a href="http://arxiv.org/abs/math/0012231">A mass formula for unimodular lattices with no roots</a>, Mathematics of Computation 72:242 (2003), pp. 839-863.
%H Steven R. Finch, <a href="http://www.people.fas.harvard.edu/~sfinch/">Minkowski-Siegel mass constants</a> [Broken link]
%H Steven R. Finch, <a href="https://oeis.org/A241121/a241121.pdf">Minkowski-Siegel mass constants</a>
%Y Cf. A005134, A054907, A054908, A054911.
%K nonn,nice,hard
%O 0,3
%A _N. J. A. Sloane_, May 23 2000
%E The classical mass formula shows that the next term is at least 8*10^7.
%E 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)