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 A002519 Theta series of 28-dimensional unimodular lattice with no roots and a parity vector of norm 4. 2
 1, 0, 0, 1728, 106472, 1734912, 19335168, 141575552, 805208040, 3725209088, 14647517184, 50579062848, 156715230240, 443680116992, 1162915024896, 2851005884544, 6596700471272, 14509559545344, 30507866603520 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,4 REFERENCES R. Bacher and B. B. Venkov, Reseaux entiers unimodulaires sans racine en dimension 27 et 28, in Reseaux euclidiens, designs spheriques et formes modulaires, pp. 212-267, Enseignement Math., Geneva, 2001. LINKS Vaclav Kotesovec, Table of n, a(n) for n = 0..2000 R. Bacher and B. B. Venkov, Reseaux entiers unimodulaires sans racine en dimension 27 et 28 (html, ps). FORMULA t3^28-56*t3^20*D8+280*t3^12*D8^2-512*t3^4*D8^3 where t3=theta3(z) and D8=(theta2(z)theta4(z))^4/16 MATHEMATICA terms = 19; t2 = EllipticTheta[2, 0, z]; t3 = EllipticTheta[3, 0, z]; t4 = EllipticTheta[4, 0, z]; D8 = (t2*t4)^4/16; s = t3^28 - 56*t3^20*D8 + 280*t3^12*D8^2 - 512*t3^4*D8^3 + O[z]^terms; CoefficientList[s, z] (* Jean-François Alcover, Jul 06 2017 *) CROSSREFS Cf. A002520. Sequence in context: A017523 A237490 A223324 * A052068 A289210 A289209 Adjacent sequences:  A002516 A002517 A002518 * A002520 A002521 A002522 KEYWORD nonn AUTHOR EXTENSIONS More terms from Kok Seng Chua (chuaks(AT)ihpc.nus.edu.sg), Jul 04 2000 STATUS approved

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