This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A008693 #20 Mar 04 2020 13:52:59 %S A008693 1,336,188496,16857792,397539408,4631004000,34415623872,187484309376, %T A008693 814908160080,2975513303952,9486512350560,27053125549632, %U A008693 70486112362176,169930901206752,384163721375616 %N A008693 Theta series of Niemeier lattice of type D_8^3. %D A008693 J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 407. %H A008693 G. C. Greubel, <a href="/A008693/b008693.txt">Table of n, a(n) for n = 0..1000</a> %F A008693 This series is the q-expansion of (7*E_4(z)^3 + 2*E_6(z)^2)/9. - _Daniel D. Briggs_, Nov 25 2011 %t A008693 terms = 15; th = EllipticTheta; E4 = 1 + 240*Sum[k^3*(q^k/(1 - q^k)), {k, 1, terms}] + O[q]^terms; E6 = th[2, 0, q]^12 + th[3, 0, q]^12 - 33*th[2, 0, q]^4*th[3, 0, q]^4*(th[2, 0, q]^4 + th[3, 0, q]^4); CoefficientList[(7/9)*E4^3 + (2/9)*E6^2 + O[q]^terms, q] (* _Jean-François Alcover_, Jul 05 2017 *) %Y A008693 Cf. A004009, A013973. %Y A008693 Cf. A008688 - A008692, A008694 - A008704. %K A008693 nonn %O A008693 0,2 %A A008693 _N. J. A. Sloane_