Importance of k4 and k2, 3 in topological graph theory

Outer planar graphs are a widely studied graph class with application in graph Drawing [T .Biedl, G. Kant] and with intersecting theoretical properties [S .Fesner, A.Maheshwari, J.Manning]. The outer thickness of the graph is the minimum number of outer planar into which the graph can be decomposed and outer thickness is one of the classical and standard measures of non- outer planarity of graphs. In this article we show that complete graph k4 and bipartite graph k2, 3 is very important in graph theory and we suggest the rule of programming formulation of the outer thickness problem.