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A126195
Conjectured values for maximal number of solid spheres of radius 1 that can be rolled all in touch with and on the outside surface of a sphere of radius n.
0
12, 28, 52, 83, 120
OFFSET
1,1
COMMENTS
A solid sphere of unit radius in touch with and outside a sphere of radius n occupies a projected angle of theta=2*arcsin[1/(1+n)]. (In the projection, the large sphere center, the small sphere center and the point where the tangent from the large sphere center touches the small sphere form a rectilinear triangle with hypotenuse of length 1+n and one cathetus of length 1. One of the angles in the triangle is theta/2.) Values have been obtained by reverse interpolation of these angles theta(n=1,2,3,...)=60, 38.9, 28.95,... degrees etc. from the "min separation" column of the Sloane table to the "npts" column, rounding npts down.
CROSSREFS
Sequence in context: A223454 A107707 A183053 * A248547 A164533 A034319
KEYWORD
more,nonn
AUTHOR
R. J. Mathar, Mar 07 2007, corrected Apr 03 2007
EXTENSIONS
Updated Fliege's URL - R. J. Mathar, Feb 05 2010
STATUS
approved