Abstract
Given a graph H and a positive integer n, the Turán number of H for the order n, denoted by \(\textrm{ex}(n,H),\) is the maximum size of a simple graph of order n not containing H as a subgraph. The book with p pages, denoted by \(B_p\), is the graph that consists of p triangles sharing a common edge. Bollobás and Erdős initiated the research on the Turán number of book graphs in 1975. The two numbers \(\textrm{ex}(p+2,B_p)\) and \(\textrm{ex}(p+3,B_p)\) have been determined by Qiao and Zhan. In this paper we determine the numbers \(\textrm{ex}(p+4,B_p),\) \(\textrm{ex}(p+5,B_p)\) and \(\textrm{ex}(p+6,B_p),\) and characterize the corresponding extremal graphs for the numbers \(\textrm{ex}(n,B_p)\) with \(n=p+2,\,p+3,\,p+4,\,p+5.\)
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References
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Acknowledgements
This research was supported by the NSFC grant 12271170 and Science and Technology Commission of Shanghai Municipality grant 22DZ2229014.
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Communicated by Shariefuddin Pirzada.
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Yan, J., Zhan, X. The Turán number of book graphs. Indian J Pure Appl Math (2023). https://doi.org/10.1007/s13226-023-00467-2
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DOI: https://doi.org/10.1007/s13226-023-00467-2