OFFSET
0,3
COMMENTS
Theta series is an element of the space of modular forms on Gamma_0(16) of weight 21/2 and dimension 22 over the integers. - Andy Huchala, May 10 2023
REFERENCES
J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 174.
LINKS
G. Nebe and N. J. A. Sloane, Home page for this lattice
EXAMPLE
G.f. = 1 + 27720*q^4 + 1272320*q^6 + ...
PROG
(Magma)
prec := 5;
L := Lattice("Lambda", 21);
T<q> := ThetaSeries(L, 2*prec);
[Coefficients(T)[2*i-1] : i in [1..prec]]; // Andy Huchala, May 10 2023
CROSSREFS
KEYWORD
nonn,more
AUTHOR
EXTENSIONS
a(5)-a(16) from Andy Huchala, May 10 2023
a(17) from Robin Visser, Sep 24 2023
STATUS
approved