A023943 Theta series of laminated lattice LAMBDA_21.

1, 0, 27720, 1272320, 19707450, 163430400, 927305904, 3995658240, 14261752680, 43493359616, 118805241072, 292653344256, 671496501200, 1430857236480, 2904257385888, 5571801102336, 10326899016378, 18297213419520

Offset

0,3

Comments

Theta series is an element of the space of modular forms on Gamma_0(16) of weight 21/2 and dimension 22 over the integers. - Andy Huchala, May 10 2023

References

J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 174.

Links

Table of n, a(n) for n=0..17.

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

Index entries for sequences related to laminated lattices

Example

G.f. = 1 + 27720*q^4 + 1272320*q^6 + ...

Prog

(Magma)
prec := 5;
L := Lattice("Lambda", 21);
T<q> := ThetaSeries(L, 2*prec);
[Coefficients(T)[2*i-1] : i in [1..prec]]; // Andy Huchala, May 10 2023

Crossrefs

Sequence in context: A279091 A307114 A291458 * A210161 A358414 A096027

Adjacent sequences: A023940 A023941 A023942 * A023944 A023945 A023946

Keyword

nonn,more

Author

N. J. A. Sloane.

Extensions

a(5)-a(16) from Andy Huchala, May 10 2023

a(17) from Robin Visser, Sep 24 2023

Status

approved