Abstract
Let f 3,4(n), for a natural number n, be the largest integer m such that every K 4-free graph of order n contains an induced triangle-free subgraph of order m. We prove that for every suffciently large n, f 3,4(n)≤n 1/2(lnn)120. By known results, this bound is tight up to a polylogarithmic factor.
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