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Theta series of laminated lattice LAMBDA_18.
1

%I #10 Jun 18 2021 11:58:17

%S 1,0,7398,175104,1820448,10506240,46589382,155022336,465542694,

%T 1157492736,2774172672,5765465088,11929117248,21932052480,40953956940,

%U 68918860800,119138987808,187615014912,305761893030,456635833344,710329749696,1017103417344,1522382017536

%N Theta series of laminated lattice LAMBDA_18.

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

%H Andy Huchala, <a href="/A023940/b023940.txt">Table of n, a(n) for n = 0..20000</a>

%o (Sage)

%o e = DirichletGroup(6).0

%o M = ModularForms(e, 9, QQ)

%o bases = [_.q_expansion(30) for _ in M.integral_basis()]

%o list(sum(x*y for (x,y) in zip(bases,[1, 0, 7398, 175104, 1820448, 10506240, 46589382, 155022336, 465542694, 1157492736]))) # _Andy Huchala_, Jun 17 2021

%K nonn

%O 0,3

%A _N. J. A. Sloane_.

%E More terms from _Andy Huchala_, Jun 17 2021