An approximate formula for counting trees in a graph

In the paper, an approximate formula for counting trees in a graph is presented. The formula estimates the change in the number of trees of a reference graph after adding or removing a certain number of lines to obtain a graph with the same number of lines as the graph considered. It is assumed that the reference graph and the graph analyzed have the same number of points. It is also assumed that the number of trees of a reference graph changes with a change in the number of lines identically as in a uniform graph. Special classes of reference graphs are discussed and formulas for counting trees are given.