For a practical course, I need to divide 24 individuals in groups of 3, over several times, in such a way that every individual is paired exactly 1 time with every other individual. How can I generate these combinations?
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If I understood correctly, this seems impossible. Fix individual $1$ and think of which groups he makes. Since there are $23$ remaining individuals, and each group is formed by choosing $2$ other people, there is a parity issue here. – D. Ungaretti Sep 02 '19 at 19:15
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That is correct. You are looking for a Steiner Triple System, and they only work with $n$ individuals when $n=6k+1$ or $n=6k+3$. https://en.wikipedia.org/wiki/Steiner_system#Steiner_triple_systems – Sep 02 '19 at 19:17