A023941 - OEIS

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A023941

Theta series of laminated lattice LAMBDA_19.

1, 0, 10668, 317952, 3747430, 24569856, 117503960, 428990464, 1355705388, 3631734784, 9033649880, 19996626432, 42549627976, 82713667584, 157758704304, 279165280256, 490745951846, 808950325248, 1335670719108, 2081937198592, 3270650346456, 4874720530432

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,3

REFERENCES

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

LINKS

Andy Huchala, Table of n, a(n) for n = 0..20000

EXAMPLE

G.f.: 1 + 10668*q^4 + 317952*q^6 + 3747430*q^8 + 24569856*q^10 + 117503960*q^12 + ...

PROG

(Magma) L:=Lattice("Lambda", 19); T<q> := ThetaSeries(L, 12); T;

(Magma)

L := Lattice("Lambda", 19);

B := Basis(ThetaSeriesModularFormSpace(L), 30);

S := [1, 0, 10668, 317952, 3747430, 24569856, 117503960, 428990464, 1355705388, 3631734784, 9033649880, 19996626432, 42549627976, 82713667584, 157758704304, 279165280256, 490745951846, 808950325248, 1335670719108, 2081937198592];

Coefficients(&+[B[i] * S[i] : i in [1..20]]); // Andy Huchala, Jun 17 2021

CROSSREFS

Sequence in context: A238150 A006006 A151411 * A065320 A164565 A212075

Adjacent sequences: A023938 A023939 A023940 * A023942 A023943 A023944

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Andy Huchala, Jun 17 2021

STATUS

approved