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 A320898 #6 Oct 23 2018 20:58:39
%S A320898 1,2,4,8,64,512,2944,13568,134656,2371328,29676544,268141568,
%T A320898 2560761856,53154824192,991944441856,13085180592128,187309143556096,
%U A320898 4400237083492352,105779411022905344,1939709049732595712,37680665654471950336,882429584512554893312,23052947736212625424384
%N A320898 Expansion of e.g.f. exp(theta_3(x) - 1), where theta_3() is the Jacobi theta function.
%F A320898 E.g.f.: exp(2*Sum_{k>=1} x^(k^2)).
%F A320898 a(0) = 1; a(n) = Sum_{k=1..n} A000122(k)*k!*binomial(n-1,k-1)*a(n-k).
%p A320898 seq(coeff(series(factorial(n)*(exp(2*add(x^(k^2),k=1..n))),x,n+1), x, n), n = 0 .. 25); # _Muniru A Asiru_, Oct 23 2018
%t A320898 nmax = 22; CoefficientList[Series[Exp[EllipticTheta[3, 0, x] - 1], {x, 0, nmax}], x] Range[0, nmax]!
%t A320898 a[n_] := a[n] = Sum[SquaresR[1, k] k! Binomial[n - 1, k - 1] a[n - k], {k, 1, n}]; a[0] = 1; Table[a[n], {n, 0, 22}]
%Y A320898 Cf. A000122, A205800.
%K A320898 nonn
%O A320898 0,2
%A A320898 _Ilya Gutkovskiy_, Oct 23 2018