A274702 - OEIS

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A274702

a(n) = number of arrangements of n circles in the affine plane in which all circles share part of their boundary with the boundary of the union of all the circles.

1, 2, 6, 47

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

COMMENTS

Consider the arrangements of n circles described in A250001.

LINKS

Table of n, a(n) for n=1..4.

CROSSREFS

Leading diagonal of triangle A249752.

Cf. A250001.

Sequence in context: A306784 A078537 A145502 * A072444 A334807 A052596

Adjacent sequences: A274699 A274700 A274701 * A274703 A274704 A274705

KEYWORD

nonn,hard,more

AUTHOR

Omar E. Pol, Jul 06 2016

STATUS

approved