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Search: id:A121603
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A121603 Numbers n such that the radius of the smallest circle into which n unit circles can be packed is 1 + csc(Pi/k), where k >= 2 is an integer. +0
2
2, 3, 4, 5, 6, 7, 8, 9, 11 (list; graph; listen)
OFFSET

1,1

COMMENT

Corresponding k values are in A121604. For these n, the centers of k unit circles can form a regular k-gon with sides of length 2 centered at the center of the larger circle. From the diagrams in the link it appears likely that 13,18,19 are the next three terms.

LINKS

E. Friedman, Erich's Packing Center: "Circles in Circles"

EXAMPLE

See A121602 for the case n=11 involving a 9-gon.

CROSSREFS

Cf. A121604, A121570, A121598, A121601, A121602.

Sequence in context: A004916 A120126 A062399 this_sequence A031086 A127288 A127287

Adjacent sequences: A121600 A121601 A121602 this_sequence A121604 A121605 A121606

KEYWORD

nonn

AUTHOR

Rick L. Shepherd (rshepherd2(AT)hotmail.com), Aug 09 2006

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Last modified November 27 22:38 EST 2009. Contains 167602 sequences.


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