A288560 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.

1, 1, 2, 11, 156, 16782

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 solid pseudo-circles is a connected set).

These counts have been reduced for mirror symmetry.

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

Crossrefs

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