Claims

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1992_05_01_gyarfas: Gyárfás proves that a graph whose odd cycles have k distinct lengths has chromatic number at most 2k+2, with equality only when a block is the complete graph on 2k+2 vertices; refereed and credited by the site's curator.

2020_12_19_gao_huo_ma: Gao, Huo and Ma prove that a graph of chromatic number at least 2k+3 has cycles of k+1 consecutive odd lengths, which strengthens the inequality of Problem 58 but does not address its equality case.

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