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A029696 Theta series of 7-dimensional lattice Kappa_7*. 1

%I #18 Jul 24 2021 01:08:58

%S 1,0,0,0,0,0,0,0,0,0,0,0,2,0,0,0,22,0,0,64,0,0,0,0,40,0,0,64,44,0,0,0,

%T 0,0,0,0,80,0,0,0,240,0,0,448,0,0,0,0,112,0,0,384,480,0,0,0,0,0,0,0,

%U 220,0,0,0,450,0,0,1408,0,0,0,0,480,0,0,960,812

%N Theta series of 7-dimensional lattice Kappa_7*.

%D J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 161.

%H Sean A. Irvine, <a href="/A029696/b029696.txt">Table of n, a(n) for n = 0..1000</a>

%H Sean A. Irvine, <a href="https://github.com/archmageirvine/joeis/blob/master/src/irvine/oeis/a029/A029696.java">Java program</a> (github)

%H G. Nebe and N. J. A. Sloane, <a href="http://www.math.rwth-aachen.de/~Gabriele.Nebe/LATTICES/KAPPAs7.html">Home page for this lattice</a>

%e G.f. = 1 + 2*q^12 + 22*q^16 + ...

%o (Magma)

%o L := Dual(Lattice("Kappa", 7));

%o B := Basis(ThetaSeriesModularFormSpace(L), 100);

%o S := [1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 22, 0, 0, 64, 0, 0, 0, 0, 40, 64];

%o Coefficients(&+[B[i] * S[i] : i in [1..26]]); // _Andy Huchala_, Jul 24 2021

%Y Cf. A015236.

%K nonn

%O 0,13

%A _N. J. A. Sloane_

%E More terms from _Sean A. Irvine_, Mar 02 2020

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Last modified April 18 18:58 EDT 2024. Contains 371781 sequences. (Running on oeis4.)