M. Liang, S.P. Radziszowski, X Xu
A note on upper bounds for some generalized Folkman numbers
Discussiones Mathematicae Graph Theory
Received 29.09.2017, Revised 10.01.2018, Accepted 10.01.2018, doi: 10.7151/dmgt.2120
We present some new constructive upper bounds based on product graphs for generalized vertex Folkman numbers. They lead to new upper bounds for some special cases of generalized edge Folkman numbers, including the cases Fe(K3,K4-e; K5) ≤ 27 and Fe(K4-e,K4-e; K5) ≤ 51. The latter bound follows from a construction of a K5-free graph on 51 vertices, for which every edge coloring with two colors contains a monochromatic K4-e.
Folkman number, Ramsey number