login
A008431
Theta series of D_9 lattice.
5
1, 144, 2034, 7392, 22608, 44640, 93984, 141120, 262386, 343536, 557280, 703584, 1068384, 1234080, 1851264, 2057280, 2884176, 3231936, 4428242, 4639392, 6455520, 6670272, 8814816, 9320256, 12065568, 12152880, 16161120, 16124544, 20496960, 20906208, 26378880, 25736832
OFFSET
0,2
REFERENCES
J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 118.
LINKS
FORMULA
Expansion of 1/2 (EllipticTheta(3, 0, q)^9 + EllipticTheta(4, 0, q)^9) (formula given by Mathematica's LatticeData(D9)). - Jean-François Alcover, Jul 07 2017
MATHEMATICA
terms = 24; s = 1/2 (EllipticTheta[3, 0, q]^9 + EllipticTheta[4, 0, q]^9) + O[q]^(2 terms); CoefficientList[s, q^2] (* Jean-François Alcover, Jul 07 2017 *)
CROSSREFS
Sequence in context: A356731 A368508 A066445 * A250084 A280025 A223687
KEYWORD
nonn,easy
EXTENSIONS
More terms from Seiichi Manyama, Oct 16 2018
STATUS
approved