OFFSET
0,2
REFERENCES
J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 102.
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..419
MATHEMATICA
nmax = 25; CoefficientList[Series[EllipticTheta[3, 0, x]^(-21/2), {x, 0, nmax}], x] * Range[0, nmax]! (* Vaclav Kotesovec, Oct 23 2018 *)
CROSSREFS
KEYWORD
sign
AUTHOR
STATUS
approved