Definition:Stirling Numbers/Historical Note

Historical Note on Stirling Numbers
This formula for the Stirling numbers of the second kind:
 * $\displaystyle x^n = \sum_k \left\{ {n \atop k}\right\} x^{\underline k}$

was the reason started his studies of the Stirling numbers in the first place.

They were studied in detail in his of $1730$.