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 A008665 Theta series of direct sum of 2 copies of b.c.c. lattice. 1
 1, 0, 0, 16, 12, 0, 64, 96, 60, 0, 0, 240, 160, 0, 384, 416, 252, 0, 0, 720, 312, 0, 960, 1056, 544, 0, 0, 1312, 960, 0, 1664, 1920, 1020, 0, 0, 2496, 876, 0, 2880, 2720, 1560, 0, 0, 3696, 2400, 0, 4224, 4416 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,4 REFERENCES J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 116. LINKS Table of n, a(n) for n=0..47. Index entries for sequences related to b.c.c. lattice FORMULA G.f.: (theta_3(z)*theta_3(z)*theta_3(z)+theta_2(z)*theta_2(z)*theta_2(z))^2. MATHEMATICA terms = 48; t2 = EllipticTheta[2, 0, z]; t3 = EllipticTheta[3, 0, z]; s = Normal[(t3^3 + t2^3)^2 + O[z]^terms] /. z -> z^4 // Simplify[#, z > 0]&; CoefficientList[s, z][[1 ;; terms]] (* Jean-François Alcover, Jul 06 2017 *) CROSSREFS Sequence in context: A225842 A298450 A028695 * A076823 A070551 A028493 Adjacent sequences: A008662 A008663 A008664 * A008666 A008667 A008668 KEYWORD nonn,easy AUTHOR N. J. A. Sloane. STATUS approved

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Last modified September 21 15:01 EDT 2023. Contains 365502 sequences. (Running on oeis4.)