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 A247660 #11 Oct 10 2018 03:24:47
%S A247660 1,2,15,229,5298,177661,8605831,601894158,60571434501,8716575772821,
%T A247660 1780241773757704,511992638746006383,205785031866223973343,
%U A247660 114780183140747719353332,88271680420025831479693219,93054995762621287409298093049
%N A247660 Number of bi-indecomposable topologies on n labeled points.
%H A247660 L. Foissy and C. Malvenuto, <a href="http://arxiv.org/abs/1407.0476">The Hopf algebra of finite topologies and T-partitions</a>, arXiv preprint arXiv:1407.0476 [math.RA], 2014.
%F A247660 G.f.: (-2+3*f(x)-f(x)^2)/f(x), where f(x) is the g.f. of A000798.
%t A247660 A000798 = {1, 1, 4, 29, 355, 6942, 209527, 9535241, 642779354, 63260289423, 8977053873043, 1816846038736192, 519355571065774021, 207881393656668953041, 115617051977054267807460, 88736269118586244492485121, 93411113411710039565210494095, 134137950093337880672321868725846, 261492535743634374805066126901117203};
%t A247660 f[x_] = Sum[A000798[[n+1]] x^n, {n, 0, nmax = Length[A000798]-1}];
%t A247660 CoefficientList[(-2 + 3 f[x] - f[x]^2)/f[x] + O[x]^nmax, x][[2 ;; -2]] (* _Jean-François Alcover_, Oct 10 2018 *)
%Y A247660 Cf. A000598, A247659.
%K A247660 nonn
%O A247660 1,2
%A A247660 _N. J. A. Sloane_, Oct 05 2014