アポロニウス超球群(Extended Apollonius Problem)といっても3次元以上は中々見つからんのぅ
http://en.wikipedia.org/wiki/Apollonius%27_problem
http://mathworld.wolfram.com/ApolloniusProblem.html
http://www.mathpages.com/home/kmath113/kmath113.htm
http://www.uni.edu/ajur/v3n1/Gisch%20and%20Ribando.pdf

掘り出し物見っけた,R.J. GREGORAC「Feuerbach's Relation and Ptolemy's Theorem in R^n」
http://www.springerlink.com/content/qt444400412117jx/