

A022071


Theta series of D*_18 lattice.


1



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
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OFFSET

0,3


REFERENCES

J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", SpringerVerlag, 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



