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

0,3

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

Formula

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

Example

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

Prog

(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

Crossrefs

Sequence in context: A205035 A205283 A251354 * A162866 A236132 A204311

Adjacent sequences: A004668 A004669 A004670 * A004672 A004673 A004674

Keyword

nonn

Author

N. J. A. Sloane

Status

approved