1. Introduction
Beginning with Carlitz’s degenerate Bernoulli polynomial and degenerate Euler polynomial [
1], many scholars in the field of mathematics have been working on degenerate versions of special polynomials and numbers which include the degenerate Stirling numbers of the first and second kinds, the degenerate Bernstein polynomials, the degenerate Bell numbers and polynomials, the degenerate gamma function, the degenerate gamma random variables, degenerate coloring and so on [
2,
3,
4,
5,
6,
7,
8,
9,
10,
11,
12,
13,
14,
15,
16,
17]. They have been studied by various ways like combinatorial methods, umbral calculus techniques, generating functions, differential equations and probability theory, etc. We can find the motivation to study degenerate polynomials and numbers in the following real world examples. Suppose the probability of a baseball player getting a hit in a match is p. We wonder if the probability that the player will succeed in the 6th trial after failing 4 times in 5 trials is still p. We can see cases where the probability is less than p because of the psychological burden that the player must succeed in the 6th trial.
In particular, the umbral calculus, based on the modern idea of linear functions, linear operators and adjoints, began to build a rigorous foundation by Rota in the 1970s, primarily as symbolic techniques for the manipulation of numerical and polynomial sequences [
18]. One of the important tools in the study of degenerate polynomials and numbers is the umbral calculus [
16,
17,
18,
19,
20,
21]. Kim Kim recently introduced the degenerate umbral calculus [
15]. Furthermore, Kim et al. [
13] studied the degenerate derangement polynomials of order
s (
) and numbers, investigate some properties of those polynomials without using degenerate umbral calculus. Motivated by Kim et al.’s work, the author considers the degenerate derangement polynomials of order
s (
) and give an example of the derangement number of order
s in real-life. In addition, the author gives their connections with the degenerate derangement polynomials of order
s and the well-known special polynomials and numbers.
First, we provide the definitions and properties required for this paper. Let
n objects be labelled
. An arrangement or permutation in which object
i is not placed in the
i-th place for any
i is called a derangement. The number of derangements of an
n-element set is called the
nth derangement number and denoted by
. The
nth derangement number is given by [
13,
22,
23,
24]
We note that the generating function of the
nth derangement number is given by [
12,
13,
25]
From (
1), Kim et al. naturally considered the derangement polynomials and degenerate derangement polynomials, respectively, which are given by [
13,
24]
and
When , , is the n-th derangement numbers.
When , is called the degenerate derangement numbers and .
For any nonzero
, the degenerate exponential function is defined by [
1,
3,
4,
5,
6,
7,
8,
9,
10,
11,
12,
13]
By Taylor expansion, we get
where
.
It was known [
25] that
where
.
For
, it is well known that the Stirling numbers of the first and second kind, respectively, are given by [
1,
4,
5,
6,
7]
and
where
,
.
Moreover, the degenerate Stirling numbers of the first and second kind, respectively, are given by [
4,
5,
6,
7]
and
Let
be the complex number field and let
be the set of all power series in the variable
t over
with
Let
and
be the vector space all linear functional on
.
Then is an -dimensional vector space over .
Recently, Kim-Kim [
15] considered
-linear functional and
-differential operator as follows:
For
and a fixed nonzero real number
, each
gives rise to the linear functional
on
, called
-linear functional given by
, which is defined by
For , we observe that the linear functional agrees with the one in , .
From
and (
10), we note that
for all
, where
is the Kronecker’s symbol.
From (
11), for each
, and each nonnegative integer
k, the differential operator on
is given by [
15]
and for any power series
,
.
The order of a power series is the smallest integer k for which the coefficient of does not vanish. The series is called invertible if . is called a delta series if and it has a compositional inverse of with .
Let
and
be a delta series and an invertible series, respectively, and
be a degenerate polynomial of a degree
n. Then there exists a unique sequences
such that the orthogonality conditions [
15]
The sequences are called the -Sheffer sequences for , which are denoted by .
The sequence
if and only if
Assume that for each of the set of nonzero real numbers, is -Sheffer for . Assume also that and , for some delta series and an invertible series . Then , where is the compositional inverse of with . Let .
In this case, Kim-Kim called that the family of -Sheffer sequences are the degenerate (Sheffer) sequences for the Sheffer polynomial .
Let
and
,
. Then
2. Degenerate Derangement Polynomials Order Arising from Degenerate Sheffer Sequences
In this section, we consider the degenerate derangement polynomials of order s, and give a combinatorial meaning of these numbers and noble identities related to these polynomials and the well-known special polynomials and numbers arising from degenerate Sheffer sequences.
From (
3), naturally, we can consider the degenerate derangement polynomials of order
s (c.f. [
13]) which is given by
When , is called the degenerate derangement numbers of order s and . When , , and , .
It is known (see [
15]) that for
,
From (
18), by the mathematical induction, for
, we get
where
Therefore, from (
19), we get
From (
21), when
, we can give a combinatorial meaning about derangement numbers of order
s in real-life.
Example 1. Suppose n players play a card game randomly divided into s rooms. In addition, assume everyone wears a hat and hangs it on the entrance wall when entering a room. If all the lights suddenly turn out during the game, how many ways no one takes his hat when everyone comes out at same time?
2.1. Connection with the Degenerate Lah–Bell Polynomials
The unsigned Lah number
counts the number of ways of all distributions of
n balls, labelled
among
k unlabelled, contents-ordered boxes, with no box left empty and have an explicit formula [
26,
27]
From (
22), the generating function of
is given by [
6,
23]
From (
23), Kim-Kim naturally introduced the Lah–Bell polynomials and the degenerate Lah–Bell polynomials, respectively, which are given by [
26,
27]
and
When , are called the Lah–Bell numbers.
When , are called the n-th degenerate Lah–Bell numbers.
When , are the n-th Lah–Bell numbers.
Theorem 1. For and , we have As the inversion formula of (25), we have Proof. From (
14), (
16) and (
24), we consider the following two Sheffer sequence as follows:
From (
15), (
16), (
23) and (
27), we have
where
Therefore, from (
28) and (
29) we have the identity (
25).
To find the inversion formula of (
25), from (
15) and (
27), we have
where, by using (
5), (
23) and (
24)
Therefore, from (
30) and (
31), we have the identity (
26). □
2.2. Connection with the Degenerate r-Extended Lah–Bell Polynomials
The
r-Lah number
counts the number of partitions of a set with
elements into
ordered blocks such that
r distinguished elements have to be in distinct ordered blocks and an explicit formula of
(see [
8,
24,
26,
28,
29,
30]) given by
From (
32), we have the generating function of
given by [
28,
29,
30]
Recently, Kim-Kim introduced the
r-extended Lah–Bell polynomials, respectively, as follows [
30]:
When , and are called the Lah–Bell numbers and r-extended Lah–Bell numbers respectively.
From (
34), naturally, KL defined a degenerate
r-extended Lah–Bell polynomials [
31] by
When , is called the n-th degenerate r-extended Lah–Bell number.
As , is the n-th r-extended Lah–Bell number.
Theorem 2. For and , we have As the inversion formula of (36), we have Proof. From (
14), (
16) (
35), we consider the following two degenerate Sheffer sequences.
From (
15), (
16), (
33) and (
38), we have
where
Therefore, from (
39) and (
40), we have the identity (
36).
To find the inversion formula of (
36), from (
15) and (
38), we have
where, by using (
5), (
24) and (
34)
Therefore, from (
41) and (
42) we have the identity (
37). □
2.3. Connection with the Degenerate Bernoulli Polynomials of Higher Order r
The degenerate Bernoulli polynomials of order
r are given by the generating function [
1,
6,
21] to be
We note that are called the degenerate Bernoulli numbers of order r.
From (
20), we observe that
Theorem 3. For and , we have In particular, when , as the inversion formula of (45), we have Proof. From (
14), (
16) and (
43), we consider the following two degenerate Sheffer sequences.
From (
15) and (
47), we have
where
For
, from (
9), we note that
Now, by using (
4), (
16) and (
50), we have
For and , we have the same result when .
For
, we note that
and
. Thus, we have
Therefore, from (
48), (
49), (
51) and (
52), we have the identity (
45).
In particular, when
, to find the inversion formula of (
45), from (
4), (
15), (
44) and (
47), we have
where
Therefore, from (
53) and (
54), we have the identity (
46). □
2.4. Connection with the Degenerate Frobenius–Euler Polynomials of Order r
Kim et al. introduced the degenerate Frobenius–Euler polynomials of order
r [
20] defined by
When , are called the degenerate Frobenius–Euler numbers of order r.
When and , are called the degenerate Frobenius–Euler numbers.
When
, the degenerate Euler polynomials of order
r respectively are given by the generating function [
1,
21] to be
We note that , are called the degenerate Euler numbers of order r.
When and , are called the degenerate Euler numbers.
From (
20), in the same way as (
44), we have
and
Theorem 4. For , we have In particular, when , as the inversion formula of (59), we have Proof. From (
15), (
16) and (
55), we consider the following two degenerate Sheffer sequences.
By using (
4), (
15), (
16) and (
61), we have
where
Therefore, from (
62) and (
63), we get the identity (
59).
In particular, when
, to find the inversion formula of (
59), by (
4), (
13), (
15) and (
61),
Therefore, from (
64) and (
65), we have the identity (
60). □
When in Theorem 3, we have the following corollary.
Corollary 1. For and , we have In particular, when , the inversion formula of (66), we have 2.5. Connection with the Degenerate Daehee Polynomials of Order r
The degenerate Daehee polynomials of order
r [
11] is defined by
where
and
. When
,
are called the degenerate Daehee numbers of order
r.
Theorem 5. For and , we have As the inversion formula of (68), we have Proof. From (
14), (
16) and (
67), we consider the following two degenerate Sheffer sequences.
In addition, from (
9), we note that
Thus from (
15), (
16), (
70) and (
71), we have
where
Therefore, from (
72) and (
73), we get the identity (
68).
To find the inversion formula of (
68), from (
8), (
13), (
15) and (
67) we have
where,
□
2.6. Connection with the Degenerate Bell Polynomials
The Bell polynomials are defined by the generating function [
4,
5,
6]
Kim-Kim introduced the degenerate Bell polynomial [
4] given by
Theorem 6. For and , we have As the inversion formula of (77), we have Proof. From (
14), (
16) and (
76), we consider two degenerate Sheffer sequences as follows:
By using (
8),(
15), (
16), (
30) and (
79), we have
where
Therefore from (
80) and (
81), we get the identity (
77).
To find inversion formula of (
77), from (
15) and (
79) we have
Thus, by using (
4), (
9) and (
76), we have
Therefore, from (
82) and (
83), we have the identity (
78). □
2.7. Connection with the Falling Factorial Polynomials
Theorem 7. For , we have Proof. Since
, we have
. We consider the two degenerate Sheffer sequences as follows:
Thus, from (
9), (
15), (
16) and (
85), we have
where
Therefore, from (
86) and (
87), we have the identity (
85). □