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Theta series of D*_26 lattice.
1

%I #8 Jul 15 2021 01:46:00

%S 1,0,52,0,1300,0,20800,0,239252,0,2107560,0,14797120,67108864,

%T 85155200,0,410468500,1744830464,1688240372,0,6030043240,21810380800,

%U 19043826880,0,54177864000,176227876864,141373532200,0,343594659200,1046898278400,786344740480,0

%N Theta series of D*_26 lattice.

%D J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 120.

%H Andy Huchala, <a href="/A022079/b022079.txt">Table of n, a(n) for n = 0..20000</a>

%e G.f. = 1 + 52*q^2 + 1300*q^4 + ...

%o (Sage)

%o L = [1, 0, 52, 0, 1300, 0, 20800]

%o M = ModularForms(Gamma1(4),13)

%o bases = [_.q_expansion(20) for _ in M.integral_basis()]

%o f = sum(x*y for (x,y) in zip(bases,L)); list(f)

%K nonn

%O 0,3

%A _N. J. A. Sloane_

%E More terms from _Andy Huchala_, Jul 14 2021