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 A320899 #6 Oct 23 2018 20:58:46
%S A320899 1,2,12,104,1120,14592,221824,3835904,74262528,1589016320,37181031424,
%T A320899 943547716608,25791165349888,754934109863936,23547020011929600,
%U A320899 779291847538638848,27263652732032843776,1005002283128197349376,38921431600215853760512,1579513585265275661189120
%N A320899 Expansion of e.g.f. exp(1/theta_4(x) - 1), where theta_4() is the Jacobi theta function.
%F A320899 E.g.f.: exp(-1 + Product_{k>=1} (1 + x^k)/(1 - x^k)).
%F A320899 a(0) = 1; a(n) = Sum_{k=1..n} A015128(k)*k!*binomial(n-1,k-1)*a(n-k).
%p A320899 seq(coeff(series(factorial(n)*(exp(-1+mul((1+x^k)/(1-x^k),k=1..n))),x,n+1), x, n), n = 0 .. 20); # _Muniru A Asiru_, Oct 23 2018
%t A320899 nmax = 19; CoefficientList[Series[Exp[1/EllipticTheta[4, 0, x] - 1], {x, 0, nmax}], x] Range[0, nmax]!
%t A320899 a[n_] := a[n] = Sum[Sum[PartitionsP[k - j] PartitionsQ[j], {j, 0, k}] k! Binomial[n - 1, k - 1] a[n - k], {k, 1, n}]; a[0] = 1; Table[a[n], {n, 0, 19}]
%Y A320899 Cf. A015128, A058892, A293840.
%K A320899 nonn
%O A320899 0,2
%A A320899 _Ilya Gutkovskiy_, Oct 23 2018