A008447 Theta series of A_7 lattice.

1, 56, 420, 896, 2366, 3360, 6440, 7168, 14196, 14168, 22120, 24192, 37912, 33824, 55440, 50176, 75838, 71232, 98700, 88704, 141960, 117824, 156520, 150528, 217672, 173656, 261240, 218624, 303424, 273504, 355600, 301056, 455028, 359744, 474320

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. 110.

Crossrefs

Cf. A023919 (dual).

Programs

Magma

L:=Lattice("A",7); T1 := ThetaSeries(L,60);

Mathematica

terms = 29; f[q_] = LatticeData["A7", "ThetaSeriesFunction"][-I Log[q]/Pi]; s = Series[f[q], {q, 0, 2 terms}]; DeleteCases[CoefficientList[s, q^(1/2) ] // Round, 0][[1 ;; terms]] (* Jean-François Alcover, Jul 04 2017 *)

Extensions

More terms from Sean A. Irvine, Jun 12 2019