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Plesken, J. Algebra, vol. 97 (1985) pp. 286-312
J. H. Conway and N. J. A. Sloane, "Low-Dimensional Lattices II: Subgroups of GL(n,Z)", Proc. Royal Soc. London, A 419 (1988), 29-68.
Table of n, a(n) for n=0..5.
G. Nebe and N. J. A. Sloane, Home page for this lattice
Sequence in context: A248984 A202374 A259415 * A075037 A134116 A122390
Adjacent sequences: A015159 A015160 A015161 * A015163 A015164 A015165
N. J. A. Sloane.