OFFSET
0,3
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..20000
G. Nebe and N. J. A. Sloane, Home page for this lattice
EXAMPLE
G.f. = 1 + 28*q^2 + 364*q^4 + ...
PROG
(Sage)
L = [1, 0, 28, 0]
M = ModularForms(Gamma1(4), 7)
bases = [_.q_expansion(20) for _ in M.integral_basis()]
f = sum(x*y for (x, y) in zip(bases, L)); list(f) # Andy Huchala, Jul 13 2021
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
More terms from Andy Huchala, Jul 13 2021
STATUS
approved