generalized Turan problem;
extremal;
MAXIMUM NUMBER;
COPIES;
PENTAGONS;
D O I:
10.7151/dmgt.2388
中图分类号:
O1 [数学];
学科分类号:
0701 ;
070101 ;
摘要:
For graphs H and F, the generalized Turan number ex(n, H, F) is the largest number of copies of H in an F -free graph on n vertices. We consider this problem when both H and F have at most four vertices. We give sharp results in almost all cases, and connect the remaining cases to well-known unsolved problems. Our main new contribution is applying the progressive induction method of Simonovits for generalized Turan problems.