Symbols:D/Derangements
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Derangement
- $D_n$ or $d_n$
A derangement is a permutation $f: S \to S$ from a set $S$ to itself where:
- $\forall s \in S: \map f s \ne s$
That is, a permutation with no fixed points.
If $S$ is finite, the number of derangements is denoted by $D_n$ or $d_n$, where $n = \card S$ (the cardinality of $S$.)
The $\LaTeX$ code for \(D_n\) is D_n
.
The $\LaTeX$ code for \(d_n\) is d_n
.
Sources
- 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): derangement