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%I #17 Mar 04 2020 18:11:02
%S 1,192,191952,16821504,397751376,4630308480,34416494784,187486720512,
%T 814895994960,2975529668544,9486529043040,27053048565504,
%U 70486165778112,169930984401024,384163663508352
%N Theta series of Niemeier lattice of type A_7^2 D_5^2.
%D J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 407.
%H G. C. Greubel, <a href="/A008698/b008698.txt">Table of n, a(n) for n = 0..1000</a>
%F This series is the q-expansion of (25*E_4(z)^3 + 11*E_6(z)^2)/36. - _Daniel D. Briggs_, Nov 25 2011
%t terms = 15; E4[q_] := 1 + 240 Sum[DivisorSigma[3, n]*q^(2 n), {n, 1, terms}]; E6[q_] := 1 - 504 Sum[DivisorSigma[5, n]*q^(2 n), {n, 1, terms}]; s = 25/36 E4[q]^3 + 11/36 E6[q]^2 + O[q]^(3 terms); Partition[ CoefficientList[s, q], 2][[All, 1]][[1 ;; terms]] (* _Jean-François Alcover_, Jul 06 2017 *)
%Y Cf. A004009, A013973.
%Y Cf. A008688 - A008697, A008699 - A008704.
%K nonn
%O 0,2
%A _N. J. A. Sloane_