Wikipedia / Stirling transform
Wikipedia / Stirling transform
In combinatorial mathematics, the Stirling transform of a sequence { an : n = 1, 2, 3, ... } of numbers is the sequence { bn : n = 1, 2, 3, ... } given by
,
is the Stirling number of the second kind, which is the number of partitions parts. This is a linear sequence transformation.
The inverse transform is
,
is a signed Stirling number of the first kind cycles.
Berstein and Sloane (cited below) state "If an is the number of objects in some class with points labeled 1, 2, ..., n (with all labels distinct, i.e. ordinary labeled structures), then bn is the number of objects with points labeled 1, 2, ..., n (with repetitions allowed)."
If
is a formal power series, and
with an and bn as above, then
.
Likewise, the inverse transform leads to the generating function identity
.
See also
References
.
Khristo N. Boyadzhiev, Notes on the Binomial Transform, Theory and Table, with Appendix on the Stirling Transform (2018), World Scientific.