[Rummikub][1] ? It encourages some logical thought and analysis. It seems to have at least one mathematical paper on it<sup>1</sup> https://doi.org/10.1093/comjnl/bxl033 and it's popular and fun. <sup>1</sup>D. Den Hertog, P. B. Hulshof, Solving Rummikub Problems by Integer Linear Programming, The Computer Journal, Volume 49, Issue 6, November 2006, Pages 665–669, https://doi.org/10.1093/comjnl/bxl033 [1]: https://en.wikipedia.org/wiki/Rummikub