A004671 Theta series of extremal even unimodular lattice in dimension 40.

1, 0, 39600, 87859200, 20779902000, 1441891123200, 46065617928000, 861717856665600, 10894640750334000, 102119813013504000, 755967560945968800, 4623420024622080000, 24151651608982497600, 110516220812493619200

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn

Examples

			G.f.: 1 + 39600*q^2 + 87859200*q^3 + ...
		

References

• J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 195.

Links

• Andy Huchala, Table of n, a(n) for n = 0..20000

Programs

Sage

e4 = eisenstein_series_qexp(4,20,normalization = "integral");
delta = CuspForms(1,12).0.q_expansion(20);
e4^5-1200*e4^2*delta  # Andy Huchala, May 07 2021

Formula

a(n) = A282015(n) - 1200 * A037945(n) - Andy Huchala, May 07 2021