

A275923


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


25




OFFSET

0,3


COMMENTS

Arrangements in A250001 that are connected (in the sense that the union of the solid circles is a connected set). See A250001, the main entry for this problem, for further information.
Is this also 1 together with column 1 of A285996?  Omar E. Pol, May 28 2017


LINKS

Table of n, a(n) for n=0..5.
Jon Wild, Figure showing relationship between A250001, A275923, A275924, and A288554 for n=3 circles


CROSSREFS

Cf. A250001, A275924, A288554A288568.
Sequence in context: A143875 A245054 A058154 * A288560 A318173 A067968
Adjacent sequences: A275920 A275921 A275922 * A275924 A275925 A275926


KEYWORD

nonn,more


AUTHOR

N. J. A. Sloane, Aug 29 2016, based on information supplied by Jon Wild.


EXTENSIONS

a(5) from Jon Wild, Aug 31 2016


STATUS

approved



