The number of spanning trees in a superprism

Let the vertices of two disjoint and equal length cycles be denoted u0, u1, . . ., un-1 in the first cycle and v0, v1, . . ., vn-1 in the second cycle for n ≥ 4. The superprism Pn is defined as the graph obtained by adding to these disjoint cycles all edges of the form uivi and uiv i+2 (mod n) .In this paper, it is proved that the number of spanning trees in Pn is n • 2 3n-2 .