The associated Stirling numbers of the first kind are defined as the number of permutations of
a given number
having exactly
permutation cycles, all
of which are of length
or greater (Comtet 1974, p. 256; Riordan 1980, p. 75).
They are a special case of the more general numbers
, and have the recurrence
relation
(1)
|
with initial conditions for
, and
(Appell 1880; Tricomi 1951; Carlitz 1958; Comtet
1974, pp. 256, 293, and 295). The generating
function for
is given by
(2)
|
(Comtet 1974, p. 256). The associated Stirling numbers of the first kind satisfy the sum identity
(3)
|
For and
a prime,
(4)
|
For all integers ,
(5)
|
and similarly,
(6)
|
(Comtet 1974, p. 256).
Special cases of the associated Stirling numbers of the first kind are given by
(7)
| |||
(8)
| |||
(9)
| |||
(10)
|
(Comtet 1974, p. 256). The triangle of these numbers is given by
(11)
|
(OEIS A008306).