A022071 Theta series of D*_18 lattice.

1, 0, 36, 0, 612, 0, 6528, 0, 48996, 262144, 275400, 0, 1207680, 4718592, 4269312, 0, 12573540, 40108032, 32041636, 0, 73617480, 218628096, 157553280, 0, 318102912, 882376704, 605381832, 0, 1090632960, 2887778304, 1888224000, 0, 3176573796, 8119910400

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

Example

G.f. = 1 + 36*q^2 + 612*q^4 + ...

Prog

(Sage)
L = [1, 0, 36, 0, 612]
M = ModularForms(Gamma1(4), 9)
bases = [_.q_expansion(40) for _ in M.integral_basis()]
f = sum(x*y for (x, y) in zip(bases, L)); list(f) # Andy Huchala, Jul 14 2021

Crossrefs

Sequence in context: A265489 A262795 A309379 * A181635 A174673 A203277

Adjacent sequences: A022068 A022069 A022070 * A022072 A022073 A022074

Keyword

nonn

Author

N. J. A. Sloane

Extensions

More terms from Andy Huchala, Jul 14 2021

Status

approved