A288567 Number of connected arrangements of n circles in the affine plane, in the sense that the union of the boundaries of the circles is a connected set and every circle intersects all the other circles.

1, 1, 1, 3, 21, 980

Offset

0,4

Comments

These counts have been reduced for mirror symmetry.

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

Links

Table of n, a(n) for n=0..5.

Crossrefs

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

Sequence in context: A340505 A327037 A144621 * A288568 A111433 A111435

Adjacent sequences: A288564 A288565 A288566 * A288568 A288569 A288570

Keyword

nonn,more

Author

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

Status

approved