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 A015691 #13 Oct 23 2018 08:15:26
%S A015691 1,-15,255,-4845,101385,-2309535,56759175,-1494125325,41881856625,
%T A015691 -1244022735375,38993819043375,-1285240980610125,44407270217165625,
%U A015691 -1604088315616161375,60431927134988784375,-2369411881012489438125
%N A015691 Expansion of e.g.f. theta_3^(-15/2).
%D A015691 J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 102.
%H A015691 Seiichi Manyama, <a href="/A015691/b015691.txt">Table of n, a(n) for n = 0..424</a>
%t A015691 nmax = 25; CoefficientList[Series[EllipticTheta[3, 0, x]^(-15/2), {x, 0, nmax}], x] * Range[0, nmax]! (* _Vaclav Kotesovec_, Oct 23 2018 *)
%K A015691 sign
%O A015691 0,2
%A A015691 _N. J. A. Sloane_