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A296406 Number of non-isomorphic arrangements of n pairwise intersecting pseudo-circles on a sphere, reduced for mirror symmetry. 7
1, 1, 1, 2, 8, 278, 145058, 447905202 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

COMMENTS

The list of arrangements is available online on the Homepage of Pseudocircles (see below) and a detailed description for the enumeration can be found in Arrangements of Pseudocircles: On Circularizability (see below).

LINKS

Table of n, a(n) for n=0..7.

S. Felsner and M. Scheucher Homepage of Pseudocircles

S. Felsner and M. Scheucher, Arrangements of Pseudocircles: On Circularizability, arXiv:1712.02149 [cs.CG], 2017.

FORMULA

a(n) = 2^(\Theta(n^2)). (cf. Arrangements of Pseudocircles: On Circularizability)

CROSSREFS

Cf. A250001, A275923, A275924, A288554-A288568, A296407-A296412, A006248.

Sequence in context: A012296 A009675 A012301 * A215651 A285850 A009501

Adjacent sequences:  A296403 A296404 A296405 * A296407 A296408 A296409

KEYWORD

nonn,more

AUTHOR

Manfred Scheucher, Dec 11 2017

STATUS

approved

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Last modified July 5 14:33 EDT 2020. Contains 335472 sequences. (Running on oeis4.)