OFFSET
0,5
REFERENCES
J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 120.
LINKS
Andy Huchala, Table of n, a(n) for n = 0..1876
EXAMPLE
G.f. = 1 + 42*q^4 + 840*q^8 + ...
PROG
(Magma)
L := Dual(Lattice("D", 21));
B := Basis(ThetaSeriesModularFormSpace(L), 60);
S := [1, 0, 0, 0, 42, 0, 0, 0, 840, 0, 0];
Coefficients(&+[B[i] * S[i] : i in [1..11]]); // Andy Huchala, Jul 14 2021
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
More terms from Andy Huchala, Jul 14 2021
STATUS
approved