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 A047805 Duplicate of A008695. 0
 1, 288, 189648, 16845696, 397610064, 4630772160, 34415914176, 187485113088, 814904105040, 2975518758816, 9486517914720, 27053099888256, 70486130167488, 169930928938176, 384163702086528 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Original title: Theta series of Niemeier lattice of type E_6^4. LINKS Table of n, a(n) for n=0..14. FORMULA This series is the q-expansion of 3/4 E_4(z)^3 + 1/4 E_6(z)^2. Cf. A004009, A013973. MATHEMATICA 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 = 3/4 E4[q]^3 + 1/4 E6[q]^2 + O[q]^(3 terms); Partition[ CoefficientList[s, q], 2][[All, 1]][[1 ;; terms]] (* Jean-François Alcover, Jul 06 2017 *) CROSSREFS Equal to theta series of A_11 D_7 E_6, cf. A008695 Sequence in context: A282102 A159299 A008695 * A173150 A282332 A291187 Adjacent sequences: A047802 A047803 A047804 * A047806 A047807 A047808 KEYWORD dead AUTHOR N. J. A. Sloane EXTENSIONS More terms and formula in terms of Eisenstein series from Daniel D. Briggs, Nov 25 2011 STATUS approved

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Last modified June 4 13:02 EDT 2023. Contains 363128 sequences. (Running on oeis4.)