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 A004407 #24 Sep 20 2018 09:17:09
%S A004407 1,-12,84,-448,2004,-7896,28224,-93312,289236,-848972,2377704,
%T A004407 -6391872,16571968,-41599320,101430144,-240877440,558440916,
%U A004407 -1266406680,2814053908,-6136337088,13148606184,-27717527552
%N A004407 Expansion of ( Sum_{n = -infinity..infinity} x^(n^2) )^(-6).
%H A004407 Seiichi Manyama, <a href="/A004407/b004407.txt">Table of n, a(n) for n = 0..10000</a>
%F A004407 a(n) ~ (-1)^n * 3^(7/4)*exp(Pi*sqrt(6*n)) / (256*2^(3/4)*n^(9/4)). - _Vaclav Kotesovec_, Aug 18 2015
%F A004407 From _Ilya Gutkovskiy_, Sep 20 2018: (Start)
%F A004407 G.f.: 1/theta_3(x)^6, where theta_3() is the Jacobi theta function.
%F A004407 G.f.: Product_{k>=1} 1/((1 - x^(2*k))*(1 + x^(2*k-1))^2)^6. (End)
%t A004407 nmax = 30; CoefficientList[Series[Product[((1 + (-x)^k)/(1 - (-x)^k))^6, {k, 1, nmax}], {x, 0, nmax}], x] (* _Vaclav Kotesovec_, Aug 18 2015 *)
%o A004407 (PARI) q='q+O('q^99); Vec(((eta(q)*eta(q^4))^2/eta(q^2)^5)^6) \\ _Altug Alkan_, Sep 20 2018
%Y A004407 Cf. A000122, A000141.
%K A004407 sign
%O A004407 0,2
%A A004407 _N. J. A. Sloane_