We present an explicit formula of the surface area of the ( n ,  k )-star graphs , i.e., |{ v | d ( e ,  v ) =  d }|, where  e is the identity node of such a graph; by identifying the cyclic structures of all the nodes in the graph, presenting a minimum routing algorithm between any node in the graph and  e , and enumerating those nodes  v , such that  d ( e ,  v ) =  d .
['Zhizhang Shen', 'Ke Qiu', 'Eddie Cheng']
On the Surface Area of the (n, k)-Star Graph