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 A015695 #13 Oct 23 2018 08:15:09
%S A015695 1,-21,483,-12075,325521,-9396765,288749475,-9398322675,322652227905,
%T A015695 -11641352627205,440043353374275,-17378800976950875,
%U A015695 715361536295492625,-30625157300600587725,1360947531581394631875,-62670194480910433291875
%N A015695 Expansion of e.g.f. theta_3^(-21/2).
%D A015695 J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 102.
%H A015695 Seiichi Manyama, <a href="/A015695/b015695.txt">Table of n, a(n) for n = 0..419</a>
%t A015695 nmax = 25; CoefficientList[Series[EllipticTheta[3, 0, x]^(-21/2), {x, 0, nmax}], x] * Range[0, nmax]! (* _Vaclav Kotesovec_, Oct 23 2018 *)
%K A015695 sign
%O A015695 0,2
%A A015695 _N. J. A. Sloane_