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..2000
EXAMPLE
G.f. = 1 + 26*q^4 + 312*q^8 + ...
PROG
(Magma)
L := Dual(Lattice("D", 13));
B := Basis(ThetaSeriesModularFormSpace(L), 20);
S := [ 1, 0, 0, 0, 26, 0, 0];
Coefficients(&+[B[i] * S[i] : i in [1..7]]); // Andy Huchala, Jul 13 2021
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved