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Number of n-dimensional odd unimodular lattice (or quadratic forms).
6

%I #14 Jul 02 2021 09:42:43

%S 0,1,1,1,1,1,1,1,1,2,2,2,3,3,4,5,6,9,13,16,28,40,68,117,273,665,2566,

%T 17059,374062

%N Number of n-dimensional odd unimodular lattice (or quadratic forms).

%D Gaëtan Chenevier, Unimodular hunting, Cogent Seminar, Jul 05 2021

%D J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 49.

%H Gaëtan Chenevier, <a href="http://gaetan.chenevier.perso.math.cnrs.fr/Unimodular_hunting_oberwolfach.pdf">Unimodular hunting</a>, Modular Forms Workshop, Oberwolfach online, Feb 2021.

%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-A054909.

%K nonn,nice,hard

%O 0,10

%A _N. J. A. Sloane_, May 23 2000