%I #11 Feb 17 2019 23:01:44
%S 1,1,1,6,139,28643
%N Number of connected one-sided arrangements of n pseudo-circles in the affine plane, in the sense that the union of the boundaries of the pseudo-circles is a connected set.
%C Arrangements in A288559 that are connected, in the sense that the union of the (boundaries of the) pseudo-circles is a connected set.
%C These counts have not been reduced for mirror symmetry.
%C See A250001, the main entry for this problem, for further information.
%Y Cf. A250001, A275923, A275924, A288554-A288568.
%K nonn,more
%O 0,4
%A _N. J. A. Sloane_, Jun 13 2017, based on information supplied by _Jon Wild_ on Aug 31 2016