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Telephone number (mathematics)

In mathematics, the telephone numbers or the involution numbers form a sequence of integers that count the ways n people can be connected by person-to-person telephone calls. These numbers also describe the number of matchings (the Hosoya index) of a complete graph on n vertices, the number of permutations on n elements that are involutions, the sum of…

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Telephone number (mathematics)

Nodes44
Edges43
Triples0
Avg. degree1.95
Density0.045455
Components1

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numbers telephone number recurrence involution displaystyle two ways sum first patterns frac people also young tableaux values function permutations one

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