A022043 Theta series of D_12 lattice.

1, 264, 7944, 64416, 253704, 825264, 1938336, 4437312, 8118024, 15653352, 24832944, 42517728, 61903776, 98021616, 133522752, 201364416, 259776264, 374842512, 471023592, 653690400, 793078704, 1082704128, 1279397088, 1699194816, 1980797856, 2578950264, 2949559536

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn

References

• J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 118.

Links

• Seiichi Manyama, Table of n, a(n) for n = 0..10000
• N. Heninger, E. M. Rains and N. J. A. Sloane, On the Integrality of n-th Roots of Generating Functions, J. Combinatorial Theory, Series A, 113 (2006), 1732-1745.

Programs

Mathematica

terms = 21; f[q_] = LatticeData["D12", "ThetaSeriesFunction"][-I*Log[q]/Pi]; s = f[q] + O[q]^(2 terms); DeleteCases[CoefficientList[s, q], 0][[1 ;; terms]] (* Jean-François Alcover, Jul 06 2017 *)

Extensions

More terms from Seiichi Manyama, Oct 16 2018