A288565 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.

1, 1, 1, 6, 139, 28643

Offset: 0

Author

N. J. A. Sloane, Jun 13 2017, based on information supplied by Jon Wild on Aug 31 2016

Keywords

• nonn
• more

Comments

Arrangements in A288559 that are connected, in the sense that the union of the (boundaries of the) pseudo-circles is a connected set.

These counts have not been reduced for mirror symmetry.

See A250001, the main entry for this problem, for further information.

Crossrefs

Cf. A250001, A275923, A275924, A288554-A288568.