Magic Circles
A set of 
magic circles is a numbering of the intersections of the Circles such that the sum overall intersections is the same constant for all circles. The above sets of three and four magic circles have magic constants14 and 39 (Madachy 1979).
References
Madachy, J. S. Madachy's Mathematical Recreations. New York: Dover, p. 86, 1979.