Ramsey equivalence of $K_n$ and $K_n+K_{n-1}$

  title={Ramsey equivalence of \$K\_n\$ and \$K\_n+K\_\{n-1\}\$},
  author={Thomas F. Bloom and Anita Liebenau},
  journal={The Electronic Journal of Combinatorics},
We prove that, for $n\geqslant 4$, the graphs $K_n$ and $K_n+K_{n-1}$ are Ramsey equivalent. That is, if $G$ is such that any red-blue colouring of its edges creates a monochromatic $K_n$ then it must also possess a monochromatic $K_n+K_{n-1}$. This resolves a conjecture of Szabó, Zumstein, and Zürcher.The result is tight in two directions. Firstly, it is known that $K_n$ is not Ramsey equivalent to $K_n+2K_{n-1}$. Secondly, $K_3$ is not Ramsey equivalent to $K_3+K_{2}$. We prove that any graph… 

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