A023920 Theta series of A*_8 lattice.

1, 0, 0, 0, 18, 0, 0, 72, 0, 240, 252, 0, 0, 504, 0, 0, 1026, 0, 2160, 1512, 0, 0, 2664, 0, 0, 3528, 0, 6720, 5616, 0, 0, 6552, 0, 0, 9828, 0, 17520, 11232, 0, 0, 16380, 0, 0, 17784, 0, 30240, 24336, 0, 0, 26208, 0, 0, 35532, 0, 60480, 37296, 0, 0, 48780, 0, 0, 50400, 0

Offset

0,5

References

J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 114.

Links

Table of n, a(n) for n=0..62.

Kok Seng Chua, The Root Lattice A*n and Ramanujan's Circular Summation of Theta Functions, Proc. Amer. Math. Soc. 130 (2002), 1-8.

G. Nebe and N. J. A. Sloane, Home page for this lattice

Formula

E4(9z)+18*eta^12(9z)/eta^4(3z) (E4(9z) term because A*_8 contains E8 as a sublattice). - Kok Seng Chua, May 02 2000

Crossrefs

Cf. A004009, A033690.

Sequence in context: A072839 A156400 A008424 * A214359 A198810 A347532

Adjacent sequences: A023917 A023918 A023919 * A023921 A023922 A023923

Keyword

nonn,easy

Author

N. J. A. Sloane.

Extensions

More terms from Kok Seng Chua, Jul 29 2001

Status

approved