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 A015669 #10 Oct 23 2018 07:19:02
%S A015669 1,9,63,315,1161,8505,112455,796635,2843505,57661065,1099313775,
%T A015669 9327901275,92211082425,1678394943225,32985192014775,598006256722875,
%U A015669 4499525524118625,75554867738975625,4316991655250649375
%N A015669 Expansion of e.g.f. theta_3^(9/2).
%D A015669 J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 102.
%H A015669 Seiichi Manyama, <a href="/A015669/b015669.txt">Table of n, a(n) for n = 0..448</a>
%t A015669 nmax = 25; CoefficientList[Series[EllipticTheta[3, 0, x]^(9/2), {x, 0, nmax}], x] * Range[0, nmax]! (* _Vaclav Kotesovec_, Oct 23 2018 *)
%K A015669 nonn
%O A015669 0,2
%A A015669 _N. J. A. Sloane_