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A125564 Theta series of 5-dimensional lattice A_5^{+3}. 1

%I #13 Feb 17 2022 07:25:12

%S 1,0,30,30,0,132,90,0,270,140,0,420,270,0,600,360,0,840,330,0,1092,

%T 660,0,1200,810,0,1500,570,0,1980,1020,0,2190,1260,0,2280,1100,0,2460,

%U 1560,0,3360,1620,0,3780,1452,0,3360,2190,0,3930,2340,0,4620,1710,0,5400,2940

%N Theta series of 5-dimensional lattice A_5^{+3}.

%D J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 110 and 116.

%H John Cannon, <a href="/A125564/b125564.txt">Table of n, a(n) for n = 0..5000</a>

%H J. H. Conway and N. J. A. Sloane, <a href="https://doi.org/10.1098/rspa.1988.0072">Low-Dimensional Lattices I: Quadratic Forms of Small Determinant</a>, Proc. Royal Soc. London, Series A, 418 (1988), 17-41.

%H LMFDB, <a href="https://lmfdb.org/Lattice/5.162.12.1.1">Integral lattice 5.162.12.1.1</a>

%H G. Nebe and N. J. A. Sloane, <a href="https://www.math.rwth-aachen.de/~Gabriele.Nebe/LATTICES/P5.2.html">Home page for this lattice</a>

%e 1 + 30*q^4 + 30*q^6 + 132*q^10 + 90*q^12 + 270*q^16 + 140*q^18 + 420*q^22 + ...

%t al[n_, l_, p_, nn_] := Sum[Exp[-2 Pi I k l/n] EllipticTheta[3, Pi k/n, q^p]^n, {k, n}] / n / Sum[q^(p n (m + l/n)^2), {m, -nn, nn}] + O[q]^nn;

%t as[n_, s_, nn_] := CoefficientList[FullSimplify[Normal@Sum[al[n, l, n/s, nn], {l, s, n, s}]], q];

%t as[6, 1, 30] (*A023917*)

%t as[6, 2, 30][[;; ;; 2]] (*this sequence*)

%t as[6, 3, 30] (*A125561*)

%t (* _Andrey Zabolotskiy_, Feb 17 2022 *)

%Y Cf. A008445, A125561, A023917.

%K nonn

%O 0,3

%A _N. J. A. Sloane_, Jan 31 2007

%E Typo in name corrected by _Andrey Zabolotskiy_, Feb 16 2022

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Last modified April 18 10:01 EDT 2024. Contains 371779 sequences. (Running on oeis4.)