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 A015690 #13 Oct 23 2018 08:15:17
%S A015690 1,-13,195,-3315,62673,-1299285,29228355,-707636475,18316505025,
%T A015690 -504116658045,14685387955875,-451033728019875,14555826008348625,
%U A015690 -492141539705941125,17387673626552904675,-640456882350467056875
%N A015690 Expansion of e.g.f. theta_3^(-13/2).
%D A015690 J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 102.
%H A015690 Seiichi Manyama, <a href="/A015690/b015690.txt">Table of n, a(n) for n = 0..425</a>
%t A015690 nmax = 25; CoefficientList[Series[EllipticTheta[3, 0, x]^(-13/2), {x, 0, nmax}], x] * Range[0, nmax]! (* _Vaclav Kotesovec_, Oct 23 2018 *)
%K A015690 sign
%O A015690 0,2
%A A015690 _N. J. A. Sloane_