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 A015687 #14 Oct 23 2018 08:14:38
%S A015687 1,-11,143,-2145,36201,-675675,13777335,-304008705,7204902705,
%T A015687 -182276917515,4897582264575,-139156370978625,4165687398497625,
%U A015687 -130958825020098075,4311426211189071975,-148272233495263502625
%N A015687 Expansion of e.g.f. theta_3^(-11/2).
%D A015687 J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 102.
%H A015687 Charles R Greathouse IV, <a href="/A015687/b015687.txt">Table of n, a(n) for n = 0..427</a>
%t A015687 nmax = 25; CoefficientList[Series[EllipticTheta[3, 0, x]^(-11/2), {x, 0, nmax}], x] * Range[0, nmax]! (* _Vaclav Kotesovec_, Oct 23 2018 *)
%o A015687 (PARI) default(seriesprecision,16)
%o A015687 th3=1+Ser(sum(i=1,sqrtint(default(seriesprecision)),2*'x^i^2))
%o A015687 Vec(serlaplace(th3^(-11/2))) \\ _Charles R Greathouse IV_, Aug 17 2017
%Y A015687 Cf. A000122, A015671.
%K A015687 sign
%O A015687 0,2
%A A015687 _N. J. A. Sloane_