Lower bounds on size and independence in K4-free graphs

We investigate lower bounds on the size of K₄-free graphs. For several ranges of independence relative to order and for graphs with maximum degree 3 and 4, we find sharp lower bounds. We also evaluate Ramsey-type numbers over the classes of graphs with maximum degree 3 and with maximum degree 4. © 1997 John Wiley & Sons, Inc. J Graph Theory 26: 61–71, 1997