Stirling Numbers
Stirling Numbers have a rich and deep history which is punctuated by stops and starts.
Citations
[1]
Incense ritual — Commutation_Relations_Normal_Ordering_and_Stirling_Numbers-9781466579897.pdf, p. 26 [ref]
"The first known application of set partitions arose in the context of tea ceremonies and incense games in Japanese upper-class society around 1500. Guests at a Kado ceremony would be smelling cups with burned incense with the goal to either identify the incense or to identify which cups contained identical incense. "