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 A022074 Theta series of D*_21 lattice. 1
 1, 0, 0, 0, 42, 0, 0, 0, 840, 0, 0, 0, 10640, 0, 0, 0, 95802, 0, 0, 0, 652848, 2097152, 0, 0, 3504816, 0, 0, 0, 15266880, 44040192, 0, 0, 55350120, 0, 0, 0, 171361498, 440401920, 0, 0, 465944304, 0, 0, 0, 1145653488, 2833252352, 0, 0, 2610853840, 0, 0, 0 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,5 REFERENCES J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 120. LINKS Andy Huchala, Table of n, a(n) for n = 0..1876 EXAMPLE G.f. = 1 + 42*q^4 + 840*q^8 + ... PROG (Magma) L := Dual(Lattice("D", 21)); B := Basis(ThetaSeriesModularFormSpace(L), 60); S := [1, 0, 0, 0, 42, 0, 0, 0, 840, 0, 0]; Coefficients(&+[B[i] * S[i] : i in [1..11]]); // Andy Huchala, Jul 14 2021 CROSSREFS Sequence in context: A095189 A023932 A243831 * A335188 A263303 A263288 Adjacent sequences:  A022071 A022072 A022073 * A022075 A022076 A022077 KEYWORD nonn AUTHOR EXTENSIONS More terms from Andy Huchala, Jul 14 2021 STATUS approved

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Last modified September 28 00:46 EDT 2021. Contains 347698 sequences. (Running on oeis4.)