Enumerating rooted simple planar maps (Q1097898)

The main purpose of this paper is to find the number of combinatorially distinct rooted simple planar maps, i.e., maps having no loops and no multi-edges, with the edge number given. We have obtained the following results. 1. The number of rooted boundary loopless planar [m,2]-maps. i.e., maps in which there are no loops on the boundaries of the outer faces, and the edge number is m, the number of edges on the outer face boundaries is 2, is \[ G^ N_ m=1,\;if\;m=1,2; \] \[ G^ N_ m=4\cdot 3^{m- 3}\frac{(7m+4)(2m-3)!}{(m-2)!(m+2)!},\;if\;m\geq 3, \] for \(m\geq 1\). \(G^ N_ 0=0.\) 2. The number of rooted loopless planar [m,2]-maps is \[ G_ m^{NL}=0,\;if\;m=0; \] \[ G_ m^{NL}=\frac{6\cdot (4m-3)!}{(m- 1)!(3m)!},\;if\;m\geq 1. \] 3. The number of rooted simple planar maps with m edges \(H^ s_ m\) satisfies the following recursive formula: \[ H^ s_ m=H_ m^{NL}-\sum^{m-1}_{i=1}\gamma (i,m)H^ s_ i,\quad m\geq 2; \] \[ H^ s_ 0=H^ s_ 1=1, \] where \(H_ m^{NL}\) is the number of rooted loopless planar maps with m edges given in the author's paper [Enumeraing rooted loopless planar maps'' ``ibid. 2, No.1, 25-37 (1985)]. 4. In addition, \(\gamma\) (i,m), \(i\geq 1\), are determined by \[ \gamma (i,m)=\sum^{m-i}_{j=1}\frac{(4j)!}{(3j+1)!j!}\frac{m-j}{m-i}\gamma (i,m-j),\quad m\geq i+1;\quad \gamma (i,i)=1 \] for \(m\geq i\), \(\gamma (i,j)=0\), when \(i>j\).