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 A015672 #10 Oct 23 2018 07:19:57
%S A015672 1,13,143,1287,9321,62205,598455,7702695,78423345,647284365,
%T A015672 9370936575,174468068775,2175194446425,25400498248125,529759106051175,
%U A015672 11093219396634375,183808243512518625,2892889119253258125
%N A015672 Expansion of e.g.f. theta_3^(13/2).
%D A015672 J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 102.
%H A015672 Seiichi Manyama, <a href="/A015672/b015672.txt">Table of n, a(n) for n = 0..447</a>
%t A015672 nmax = 25; CoefficientList[Series[EllipticTheta[3, 0, x]^(13/2), {x, 0, nmax}], x] * Range[0, nmax]! (* _Vaclav Kotesovec_, Oct 23 2018 *)
%K A015672 nonn
%O A015672 0,2
%A A015672 _N. J. A. Sloane_