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 A015683 #12 Oct 23 2018 08:14:11
%S A015683 1,-5,35,-315,3345,-40845,562275,-8575875,143273025,-2598830325,
%T A015683 50790003075,-1062924352875,23699584148625,-560468936152125,
%U A015683 14004884930911875,-368541883096261875,10183347536828090625
%N A015683 Expansion of e.g.f. theta_3^(-5/2).
%D A015683 J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 102.
%H A015683 Seiichi Manyama, <a href="/A015683/b015683.txt">Table of n, a(n) for n = 0..434</a>
%t A015683 nmax = 25; CoefficientList[Series[EllipticTheta[3, 0, x]^(-5/2), {x, 0, nmax}], x] * Range[0, nmax]! (* _Vaclav Kotesovec_, Oct 23 2018 *)
%K A015683 sign
%O A015683 0,2
%A A015683 _N. J. A. Sloane_