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.

2, 3, 4, 5, 6, 7, 8, 9, 11

Offset: 1

Author

Rick L. Shepherd, Aug 09 2006

Keywords

• nonn

Comments

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.

Examples

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

Links

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

Crossrefs

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