On the Enumeration of Rooted Non-Separable Planar Maps
William G. Brown, W. T. Tutte · Canadian Journal of Mathematics · 1964
It has been shown elsewhere (1, 4) that the number of rooted non-separable planar maps with n edges is In the present paper we improve upon this result by finding the number fi,j of rooted non-separable planar maps with i + 1 vertices and j + 1 faces. We use the definitions of (1). Among the non-separable planar maps only the loop-map and the link-map have i = 0 or j = 0. We therefore confine our attention to the case in which i and j are both positive.