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A004674 Theta series of extremal even unimodular lattice in dimension 64. 1
1, 0, 0, 2611200, 19524758400, 19715347537920, 5615943999897600, 667995073382707200, 41929879624021065600, 1615294860315735244800, 42338358774994331566080, 812656958650918956288000, 12060148245903215066380800 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

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

G.f.: E4(q)^8 - 1920 * E4(q)^5 * Delta(q) + 627840 * E4(q)^2 * Delta(q)^2 with E4(q) as in A004009 and Delta(q) as in A000594. - Andy Huchala, Jun 04 2021

EXAMPLE

G.f.: 1 + 2611200*q^3 + 19524758400*q^4 + ...

PROG

(SAGE)

e4 = eisenstein_series_qexp(4, 20, normalization = "integral");

delta = CuspForms(1, 12).0.q_expansion(20);

e4^8 - 1920*e4^5*delta + 627840*e4^2*delta^2 # Andy Huchala, Jun 04 2021

CROSSREFS

Cf. A000594, A004009.

Sequence in context: A186588 A204882 A183660 * A123155 A251036 A233723

Adjacent sequences:  A004671 A004672 A004673 * A004675 A004676 A004677

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified August 9 10:09 EDT 2022. Contains 356021 sequences. (Running on oeis4.)