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A002520 Theta series of 28-dimensional unimodular lattice with no roots and with no parity vector of norm 4. 2
1, 0, 0, 2240, 98280, 1790208, 19138560, 141920640, 805208040, 3723722240, 14651449344, 50573436480, 156717687840, 443691198720, 1162883174400, 2851049534592, 6596666916840, 14509544394240, 30507984568320 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,4
LINKS
R. Bacher and B. B. Venkov, Réseaux entiers unimodulaires sans racine en dimension 27 et 28, in Réseaux euclidiens, designs sphériques et formes modulaires, pp. 212-267, Enseignement Math., Geneva, 2001.
FORMULA
t3^28-56*t3^20*D8+280*t3^12*D8^2 where t3=theta_3(z) and D8=(theta_2(z)*theta_4(z))^4/16.
MATHEMATICA
terms = 19; t3[z_] := EllipticTheta[3, 0, z]; D8[z_] := (EllipticTheta[2, 0, z]*EllipticTheta[4, 0, z])^4/16; s = t3[z]^28 - 56*t3[z]^20*D8[z] + 280*t3[z]^12*D8[z]^2 + O[z]^terms; CoefficientList[s, z] (* Jean-François Alcover, Jul 05 2017 *)
CROSSREFS
Cf. A002519.
Sequence in context: A079013 A186865 A038728 * A337416 A183771 A271470
KEYWORD
nonn,nice,easy
AUTHOR
EXTENSIONS
More terms from Kok Seng Chua (chuaks(AT)ihpc.nus.edu.sg), Jul 04 2000
STATUS
approved

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Last modified March 28 09:04 EDT 2024. Contains 371240 sequences. (Running on oeis4.)