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A008447 Theta series of A_7 lattice. 5
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

REFERENCES

J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 110.

LINKS

Table of n, a(n) for n=0..28.

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-Fran├žois Alcover, Jul 04 2017 *)

PROG

(MAGMA) L:=Lattice("A", 7); T1<q> := ThetaSeries(L, 60);

CROSSREFS

Cf. A023919 (dual).

Sequence in context: A075283 A205313 A287702 * A076647 A187159 A220048

Adjacent sequences:  A008444 A008445 A008446 * A008448 A008449 A008450

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified February 21 16:38 EST 2018. Contains 299414 sequences. (Running on oeis4.)