摘要
首先给出了l(y ,z)的参数表达式 ,然后利用拉格朗日反演得到了它的精确解 ,即得到了以根节点次、内面个数为两个参数的根面次是 2的当λ =3时的色和的精确表达式 。
A parametric expression of l(y,z) is derived,then by using lagrangian inversion,an explicit expression of chromatic sums for rooted near planar triangulations with the rooted face valency 2 and λ=3 is obtained by the valency of the root-vertex and the number of inner faces as two parameters.Furthermore,that with the number of inner faces is derived in a different and much simpler manner from what exists.