Stirling numbers of the first kind

Remarks

Other notations are $\left[ {n \atop k} \right]$ and $|s(n, k)|$. The signed numbers are $s(n, k) = (-1)^{n-k} c(n, k)$. Example: $c(3, 2) = 3$. The permutations of $\{1, 2, 3\}$ with two cycles are the three transpositions. The numbers satisfy $\sum_k c(n, k) = n!$ and $x (x + 1) \cdots (x + n - 1) = \sum_k c(n, k)\, x^k$. The values satisfy a recurrence in $n$ and $k$.