A288557 Number of connected one-sided arrangements of n circles in the affine plane, in the sense that the union of the boundaries of the circles is a connected set.

1, 1, 1, 6, 139

Offset

0,4

Comments

These counts are not reduced for mirror symmetry.

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

Links

Table of n, a(n) for n=0..4.

Crossrefs

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

Sequence in context: A366227 A155558 A053467 * A288565 A090944 A007340

Adjacent sequences: A288554 A288555 A288556 * A288558 A288559 A288560

Keyword

nonn,more

Author

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

Status

approved