Step variety: Difference between revisions
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<math>\displaystyle{\dfrac{1}{n} \sum_{d\mid n} \phi(d) \sum_{j=1}^r (-1)^{r-j} {r \choose j} j^{n/d}} \\ | <math>\displaystyle{\dfrac{1}{n} \sum_{d\mid n} \phi(d) \sum_{j=1}^r (-1)^{r-j} {r \choose j} j^{n/d}} \\ | ||
=\displaystyle{\dfrac{ | =\displaystyle{\dfrac{r!}{n} \sum_{d\mid n} \phi(d) S(n/d, r)}</math> | ||
where <math>\phi</math> is the Euler totient function and <math>S(n, | where <math>\phi</math> is the Euler totient function and <math>S(n, r)</math> is the Stirling number of the second kind for the number of ways to partition an ''n'''element set into ''r'' distinguished parts. | ||
== List of named ternary scales == | == List of named ternary scales == | ||