A023913 Theta series of A_22 lattice.

1, 506, 53130, 2029566, 35668446, 340000122, 2094317302, 9773190636, 37179208176, 120683024506, 346388200466, 897628047384, 2144673537006, 4770315795938, 10019792884332, 19955152642348, 38085959774742

Offset

0,2

References

J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 110.

Links

Table of n, a(n) for n=0..16.

Mathematica

terms = 17; f[q_] = LatticeData["A22", "ThetaSeriesFunction"][-I*Log[q]/Pi]; s =
f[q] + O[q]^(2 terms); Partition[CoefficientList[s, q] // Round, 2][[All, 1]][[1 ;; terms]] (* Jean-François Alcover, Jul 06 2017 *)

Crossrefs

Sequence in context: A295992 A122267 A204946 * A035848 A028685 A152524

Adjacent sequences: A023910 A023911 A023912 * A023914 A023915 A023916

Keyword

nonn

Author

N. J. A. Sloane.

Extensions

More terms from Robert.Harley(AT)inria.fr, see A023902.

Status

approved