A288560 - OEIS

%I #16 Jun 13 2017 13:12:00

%S 1,1,2,11,156,16782

%N Number of connected arrangements of n pseudo-circles in the affine plane, in the sense that the union of the solid pseudo-circles is a connected set.

%C Arrangements in A288559 that are connected (in the sense that the union of the solid pseudo-circles is a connected set).

%C These counts have 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 0,3

%A _N. J. A. Sloane_, Jun 13 2017, based on information supplied by _Jon Wild_ on Aug 31 2016.