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A004671 Theta series of extremal even unimodular lattice in dimension 40. 1
1, 0, 39600, 87859200, 20779902000, 1441891123200, 46065617928000, 861717856665600, 10894640750334000, 102119813013504000, 755967560945968800, 4623420024622080000, 24151651608982497600, 110516220812493619200 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,3
REFERENCES
J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 195.
LINKS
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
KEYWORD
nonn
AUTHOR
STATUS
approved

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Last modified March 29 02:23 EDT 2024. Contains 371264 sequences. (Running on oeis4.)