EUROPEAN JOURNAL OF PURE AND APPLIED MATHEMATICS 2025, Vol. 18, Issue 1, Article Number 5702 ISSN 1307-5543 – ejpam.com Published by New York Business Global Probabilistic Multiple Poly Bernoulli Polynomials of the Second Kind Si Hyeon Lee1,∗, Li Chen2 1 Kwangwoon University, Seoul 139-701, Republic of Korea 2 School of Mathematics, Xi’an University of Finance and Economics, Xi’an 710100, China Abstract. The purpose of this paper is to introduce the probabilistic multiple poly Bernoulli polynomials of the second kind under the condition that Y is a random variable. This means that we will consider the probabilistic extension of the multiple poly Bernoulli polynomials of the second kind and study to obtain some new results. Furthermore, we investigate their interesting properties. 2020 Mathematics Subject Classifications: 11B68, 11B73 Key Words and Phrases: Poly Bernoulli polynomials of the second kind, Stirling numbers, Probabilistic poly-Bernoulli polynomials, Probabilistic Bernoulli polynomials. 1. Introduction Many years ago Qi-Kim-Kim-Dolgy considered poly Bernoulli polynomials of the sec- ond kind and multiple poly Bernoulli polynomials of the secon kind in [28]. Recently, researchers considered probabilistic Stirling numbers, bell numbers, Bernoulli polynomi- als and Euler polynomials. The aim of this paper is to study probabilistic multiple poly Bernoulli polynomials of the second kind. Specifically speaking, we assume that Y is a random variable In section 1, firstly we recall polylogarithm Lik(t), multiple polyloga- rithm Lik1,...,kr(t). we remind poly Bernoulli polynomials of the second kind and Bernoulli polynomials of order α. we recall that probabilistic Stirling numbers of the second kind and Lah numbers. In section 2, we define probabilistic poly Bernoulli polynomials of the second kind b (k) n,Y and probabilistic multiple poly Bernoulli polynomials of the second kind b (k1,...,kr) n,Y associated with Y . In Theorem 2.1, we derive an expression for nb (k) n−1,Y (x). When Y ∼ Γ(1, 1) in Theorem 2.2, we get an expression for b (k) n,Y (x) as sum of the prod- ucts. When Y is the Bernoulli random variable, in Theorem 2.3 we get expression for b (k) n,Y (x). In Theorem 2.4, we obtain an expression for b (k1,...,kr) n,Y (x). In Theorem 2.5, we ∗Corresponding author. DOI: https://doi.org/10.29020/nybg.ejpam.v18i1.5702 Email addresses: ugug11@naver.com (S. H. Lee), chenli 0928@xaufe.edu.cn (L. Chen) https://www.ejpam.com 1 Copyright: © 2025 The Author(s). (CC BY-NC 4.0) S. H. Lee, L. Chen / Eur. J. Pure Appl. Math, 18 (1) (2025), 5702 2 of 13 find an expression of b (k1,...,kr) n+1,Y (x+1)−b k1,...,kr n+1,Y (x) n+1 . In Theorem 2.6, we derive an expression of b (k1,...,kr) n,Y (x) between probabilistic multi-poly-Bernoulli polynomials, Bernoulli polynomi- als of the second kind of order r and probabilistic the Stirling numbers of the second kind. In Theorem 2.7 we get an expression of b (k1,...,kr) n,Y (x+ y). Now we recall that The Bernoulli polynomials of the second kind are defined by t log(1 + t) (1 + t)x = ∞∑ n=0 bn(x) tn n! , (see[12], [13], [25], [29]). (1) The Bernoulli polynomials of the second kind with order r are defined by the generating function ( t log(1 + t) )r (1 + t)x = ∞∑ n=0 brn(x) tn n! , (r ∈ Z), (see[17]). (2) It is well known that t(1 + t)x−1 log(1 + t) = ∞∑ n=0 B(n) n (x) tn n! , (see[9], [22], [5].[7]). (3) where the Bernoulli polynomials of order α which are given by( t et − 1 )α ext = ∞∑ n=0 Bα n (x) tn n! , (see[9], [22], [5], [29], [8].[7]). (4) From (1) and (3), we note that bn(x) = B(n) n (x+ 1), (n ≥ 0), (see[9], [22]). (5) For k ∈ Z, the polylogarithm function is defined by Lik(x) = ∞∑ n=1 xn nk , (see[4], [13], [9], [22], [11], [16], [21]). (6) The poly Bernoulli polynomials of the second kind are defined by Lik(1− e−t) log(1 + t) (1 + t)x = ∞∑ n=0 b(k)n (x) tn n! , (see[9], [23]). (7) For k1, k2, . . . , kr ∈ Z, the multiple polylogarithm is defined by Lik1,...,kr(z) = ∑ 0 0. Let (Yi)i≥1 be a sequence of mutually independent copies of random variable Y , and let Sn = Y1 + · · · + Yn, (n ≥ 1), with S0 = 0. A continuous random variable Y whose density function is given by f(y) = { βe−βy (βy)α−1 Γ(α) , if y > 0, 0, if y ≤ 0, (see[13], [16], [20]), (13) for some α, β > 0 is said to be the gamma random variable with parameters α, β, which is denoted by Y ∼ Γ(α, β). The Stirling number of the second kind are defined by xn = n∑ k=0 S2(n, k)(x)k, (see[2], [19], [6], [14], [29]). (14) From (14), we also derive the generating function as follows. 1 k! (et − 1)k = ∞∑ n=k S2(n, k) tn n! , (see[2], [19], [6], [14]). (15) It is well known that the Lah numbers are defined by 1 k! ( t 1− t )k = ∞∑ n=k L(n, k) tn n! , (r ≥ 0), (see[13], [6]). (16) The probabilistic Stirling number of the second kind associated with Y are defined by 1 k! (E[eY t]− 1)k = ∞∑ n=k { n k } Y tn n! , (see[1], [13], [19]). (17) S. H. Lee, L. Chen / Eur. J. Pure Appl. Math, 18 (1) (2025), 5702 4 of 13 In [13]. Kim also considered the probabilistic multi-poly-Bernoulli polynomials associated with Y by Lik1,...,kr ( 1− E[e−Y t] ) (1− E[e−Y t])r ( E[e−Y t] )x = ∞∑ n=0 B (k1,...,kr) n,Y (x) tn n! , (see[13]). (18) 2. probabilistic poly and multiple poly Bernoulli polynomials of the second kind In this section, we consider probabilistic poly Bernoulli polynomials of the second kind associated with Y which are given by Lik(1− E[e−Y t]) log(1 + t) (1 + t)x = ∞∑ n=0 b (k) n,Y (x) tn n! . (19) When x = 0, b (k) n,Y (0) = b (k) n,Y are called probabilistic multiple poly Bernoulli numbers of the second kind. From (19), we have Proof. Theorem 1. t ∞∑ n=0 b (k) n,Y (x) tn n! = t log(1 + t) (1 + t)xLik(1− E[e−Y t]) (20) = ∞∑ l=0 B (l) l (x+ 1) tl l! ∞∑ m=1 (1− E[e−Y t])m mk = ∞∑ l=0 B (l) l (x+ 1) tl l! ∞∑ m=1 (−1)mm! mk ∞∑ j=m (−1)j { j m } Y tj j! = ∞∑ l=0 B (l) l (x+ 1) tl l! ∞∑ j=1 j∑ m=1 (−1)m+jm! mk { j m } Y tj j! = ∞∑ n=1 n∑ j=1 j∑ m=1 (−1)m+jm! mk ( n j ){ j m } Y B (n−j) n−j (x+ 1) tn n! . On the other hand, in (20) t ∞∑ n=0 b (k) n,Y (x) tn n! = ∞∑ n=1 nb (k) n−1,Y (x) tn n! . (21) Thus, by comparing the coefficients on both sides of (20) and (21), we have the following theorem. S. H. Lee, L. Chen / Eur. J. Pure Appl. Math, 18 (1) (2025), 5702 5 of 13 Theorem 1. For n ≥ 1, we have nb (k) n−1,Y (x) = n∑ j=1 j∑ m=1 (−1)m+jm! mk ( n j ){ j m } Y B (n−j) n−j (x+ 1). Let Y ∼ Γ(1, 1), then we note that E[eY t] = 1 1− t . (22) From (19) and (22), we have Proof. Theorem 2. ∞∑ n=0 b (k) n,Y (x) tn n! = t(1 + t)x tlog(1 + t) ∑ m=1 (1− 1 1−t) m mk (23) = 1 t ∞∑ i=0 bi(x) ti i! ∞∑ m=1 (−1)mm! mk 1 m! ( t 1− t )m = 1 t ∞∑ i=0 bi(x) ti i! ∞∑ m=1 (−1)mm! mk ∞∑ l=m L(l,m) tl l! = 1 t ∞∑ i=0 bi(x) ti i! ∞∑ l=1 l∑ m=1 (−1)mm! mk L(l,m) tl l! = ∞∑ n=1 n∑ l=1 l∑ m=1 ( n l ) (−1)mm! mk L(l,m)bn−l(x) tn−1 n! = ∞∑ n=0 n+1∑ l=1 l∑ m=1 ( n+ 1 l ) (−1)mm! mk L(l,m) bn−l+1(x) n+ 1 tn n! . Thus, we have the following theorem. Theorem 2. Let Y ∼ Γ(1, 1). For n ≥ 0, we have b (k) n,Y (x) = n+1∑ l=1 l∑ m=1 ( n+ 1 l ) (−1)mm! mk L(l,m) bn−l+1(x) n+ 1 . Let Y be the Bernoulli random variable with probability of success p. Then we have E[eY t] = p(et − 1) + 1. (24) By (19) and (24), we have S. H. Lee, L. Chen / Eur. J. Pure Appl. Math, 18 (1) (2025), 5702 6 of 13 Proof. Theorem 3. ∞∑ n=0 b (k) n,Y tn n! = (1 + t)x log(1 + t) ∞∑ m=1 (1− E[e−Y t])m mk (25) = (1 + t)x log(1 + t) ∞∑ m=1 (−1)mpm(et − 1)m mk = t(1 + t)x tlog(1 + t) ∞∑ m=1 (−1)mpmm! mk (et − 1)m m! = 1 t ∞∑ l=0 bl(x) tl l! ∞∑ m=1 (−1)mpmm! mk ∞∑ i=m S2(i,m) ti i! = 1 t ∞∑ l=0 bl(x) tl l! ∞∑ i=1 i∑ m=1 (−1)mpmm! mk S2(i,m) ti i! = ∞∑ n=1 n∑ i=1 i∑ m=1 ( n i ) (−1)mpmm! mk S2(i,m)bn−i(x) tn−1 n! = ∞∑ n=0 n+1∑ i=1 i∑ m=1 ( n+ 1 i ) (−1)mpmm! mk S2(i,m) bn−i+1(x) n+ 1 tn n! . Thus, we have the following theorem. Theorem 3. Let Y be the Bernoulli random variable with probability of success p. For n ≥ 0, we have b (k) n,Y = n+1∑ i=1 i∑ m=1 ( n+ 1 i ) (−1)mpmm! mk S2(i,m) bn−i+1(x) n+ 1 . Now, we consider probabilistic multiple poly Bernoulli polynomials of the second kind which are given by r!Lik1,...,kr(1− E[e−Y t]) (log(1 + t))r (1 + t)x = ∞∑ n=0 b (k1,...,kr) n,Y (x) tn n! . (26) When k1 = · · · = kr = 1 and Y = 1, we note that ∞∑ n=0 b (1,...,1) n,Y (x) = ( t log(1 + t) )r (1 + t)x = ∞∑ n=0 brn(x) tn n! . (27) From (26), we have S. H. Lee, L. Chen / Eur. J. Pure Appl. Math, 18 (1) (2025), 5702 7 of 13 Proof. Theorem 4. ∞∑ n=0 b (k1,...,kr) n,Y (x) tn n! = r!(1 + t)x (log(1 + t))r Lik1,...,kr(1− E[e−Y t]) (28) = r!(1 + t)x (log(1 + t))r ∑ 0