OFFSET
0,3
COMMENTS
Theta series of the 23-dimensional sublattice of the Leech lattice orthogonal to any norm 4 vector
REFERENCES
J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 174.
LINKS
Andy Huchala, Table of n, a(n) for n = 0..20000
G. Nebe and N. J. A. Sloane, Home page for this lattice
PROG
(Magma)
L := Lattice("Lambda", 23);
B := Basis(ThetaSeriesModularFormSpace(L), 20);
S := [1, 0, 93150, 6476800, 133204500, 1384998912, 9403968600, 47406643200, 192825064350, 663509299200, 2007834672456, 5456580940800];
Coefficients(&+[B[i] * S[i] : i in [1..12]]); // Andy Huchala, Jun 29 2021
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
More terms from Kok Seng Chua (chuaks(AT)ihpc.nus.edu.sg), Sep 06 2001
a(17) - a(18) from Andy Huchala, Jun 29 2021
STATUS
approved