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A275924 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. 23
1, 1, 1, 6, 112, 15502 (list; graph; refs; listen; history; text; internal format)



Arrangements in A250001 that are connected, in the sense that the union of the (boundaries of the) circles is a connected set. See A250001, the main entry for this problem, for further information.


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

Jon Wild, Figure showing relationship between A250001, A275923, A275924, and A288554 for n=3 circles


Cf. A250001, A275923, A288554-A288568.

Sequence in context: A009612 A009798 A088668 * A288561 A291917 A066931

Adjacent sequences:  A275921 A275922 A275923 * A275925 A275926 A275927




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


a(5) corrected by Jon Wild, Aug 31 2016



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Last modified December 5 15:11 EST 2019. Contains 329753 sequences. (Running on oeis4.)