An extremal problem concerning graphs not containing image and image Original Research Article

Brualdi and Mellendorf raised the following problem as a modification of Turánʹs theorem. Let t and n be positive integers with image. Determine the maximum number of edges of a graph of order n that contains neither image nor image as a subgraph. They solved it for image (see R.A. Brualdi, S. Mellendorf, Two extremal problems in graph theory, The Electron. J. Combin. 1 (1994) #R2). We consider the following similar modification of Turánʹs theorem. Let t and n be positive integers with image. Determine the maximum number of edges of a graph of order n that contains neither image nor image as a subgraph. We solve it for image.