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Degenerate r-truncated Stirling numbers

  • For any positive integer r, the r-truncated (or r-associated) Stirling number of the second kind S(r)2(n,k) enumerates the number of partitions of the set {1,2,3,,n} into k non-empty disjoint subsets, such that each subset contains at least r elements. We introduce the degenerate r-truncated Stirling numbers of the second kind and of the first kind. They are degenerate versions of the r-truncated Stirling numbers of the second kind and of the first kind, and reduce to the degenerate Stirling numbers of the second kind and of the first kind for r=1. Our aim is to derive recurrence relations for both of those numbers.

    Citation: Taekyun Kim, Dae San Kim, Jin-Woo Park. Degenerate r-truncated Stirling numbers[J]. AIMS Mathematics, 2023, 8(11): 25957-25965. doi: 10.3934/math.20231322

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  • For any positive integer r, the r-truncated (or r-associated) Stirling number of the second kind S(r)2(n,k) enumerates the number of partitions of the set {1,2,3,,n} into k non-empty disjoint subsets, such that each subset contains at least r elements. We introduce the degenerate r-truncated Stirling numbers of the second kind and of the first kind. They are degenerate versions of the r-truncated Stirling numbers of the second kind and of the first kind, and reduce to the degenerate Stirling numbers of the second kind and of the first kind for r=1. Our aim is to derive recurrence relations for both of those numbers.



    Explorations for the degenerate versions of some special numbers and polynomials have become lively interests for some mathematicians in recent years, which began from the pioneering work of Carlitz (see [1, 2]). These have been done by employing various methods, such as generating functions, combinatorial methods, p-adic analysis, umbral calculus, operator theory, differential equations, special functions, probability theory and analytic number theory (see [5, 913, 16, 17] and the references therein).

    The Stirling number of the second kind S2(n,k) enumerates the number of partitions of the set [n]={1,2,,n} into k nonempty disjoint sets, while the r-truncated(or r-associated) Stirling number of the second kind S(r)2(n,k) counts the number of partitions of the set [n] into k non-empty disjoint subsets, such that each subset contains at least r elements, for any positive integer r. The reader refers to [7] for further details on the r-associated Stirling numbers of the first kind and of the second kind. Our aim is to introduce the degenerate r-truncated Stirling numbers of the second kind and the first kind and to derive their recurrence relations. They are degenerate versions of the r-truncated Stirling numbers of the second kind and of the first kind, and reduce to the degenerate Stirling numbers of the second kind and of the first kind for r=1. Here, we mention that the degenerate Stirling numbers of both kinds appear very frequently when one studies various degenerate versions of some special numbers and polynomials.

    The outline of this paper is as follows. In Section 1, we recall the definitions and recurrence relations of the classical, the degenerate and the r-truncated Stirling numbers of both kinds. Section 2 is the main result of this paper. We introduce the degenerate r-truncated Stirling numbers of the second kind and express the degenerate r-truncated Bell polynomials in terms of the degenerate r-truncated Stirling numbers of the second kind. In Theorem 2, we derive a recurrence relation for the degenerate Stirling numbers of the second kind. We also introduce the degenerate r-truncated Stirling numbers of the first kind and deduce a recurrence relation for those numbers in Theorem 4. For the rest of this section, we recall the facts that are needed throughout this paper.

    For any nonzero λR, the degenerate exponentials are defined by

    exλ(t)=(1+λt)xλ=n=0(x)n,λn!tn,eλ(t)=e(1)λ(t),(see [1,2]), (1.1)

    where

    (x)0,λ=1,(x)n,λ=x(xλ)(x(n1)λ),(n1),(see [10,11]). (1.2)

    Let logλt be the compositional inverse of eλ(t), called the degenerate logarithm, such that logλ(eλ(t))=eλ(logλ(t))=t.

    Then, we have

    logλ(1+t)=n=1(1)n,1/λλn1n!tn,(see [9]). (1.3)

    Note that limλ0eλ(t)=et, limλ0logλ(1+t)=log(1+t).

    For k0, the Stirling numbers of the first kind are defined by

    1k!(log(1+t))k=n=kS1(n,k)tnn!,(k0),(see [3,13,14,17]). (1.4)

    The Stirling numbers of the second kind are given by

    1k!(et1)k=n=kS2(n,k)tnn!,(see [5,6,18,19,20]). (1.5)

    From (1.4) and (1.5), we have for n,k0, with nk (see [10, 15, 18])

    S1(n+1,k)=S1(n,k1)nS1(n,k),S2(n+1,k)=S2(n,k1)+kS2(n,k). (1.6)

    Recently, the degenerate Stirling numbers of the first kind and of the second kind were respectively defined by

    1k!(logλ(1+t))k=n=kS1,λ(n,k)tnn!, (1.7)

    and

    1k!(eλ(t)1)k=n=kS2,λ(n,k)tnn!,(see [9]), (1.8)

    where k is a non-negative integer.

    By (1.7) and (1.8), we get

    S1,λ(n+1,k)=S1,λ(n,k1)+(kλn)S1,λ(n,k),S2,λ(n+1,k)=S2,λ(n,k1)+(knλ)S2,λ(n,k), (1.9)

    where n,k0 with nk (see [9]).

    Note that limλ0S1,λ(n,k)=S1(n,k), limλ0S2,λ(n,k)=S2(n,k).

    The generating function of the r-truncated Stirling numbers of the second kind is given by

    1k!(etr1l=0tll!)k=n=rkS(r)2(n,k)tnn!,(see [4,6,7,8]). (1.10)

    Thus, by (1.10), we obtain the recursion formula of S(r)2(n,k), for n,k0 with nrk, which is given by

    S(r)2(n,k)=kS(r)2(n1,k)+(n1r1)S(r)2(nr,k1), (1.11)

    with the initial condition S(r)2(n,k)=0 if n<kr and S(r)2(n,k)=(rk)!k!(r!)k if n=rk.

    As degenerate versions of the r-truncated Stirling numbers of the second kind, we consider the degenerate r-truncated Stirling numbers of the second kind given by

    1k!(eλ(t)r1l=0(1)l,λl!tl)k=n=krS(r)2,λ(n,k)tnn!, (2.1)

    where rN and k is a non-negative integer.

    From (2.1), we note that

    S(r)2,λ(n,k)=1k!l1++lk=nlirn!(1)l1,λ(1)l2,λ(1)lk,λl1!l2!lk!=1k!km=0(km)(1)mr1l1,l2,,lm=0n!(mi=1(1)lj,λ)(km)nl1l2lm,λl1!l2!lm!(nl1l2lm)!, (2.2)

    where nkr0, k,r0.

    Note that S(r)2,λ(n,k)=0 if n<kr and S(r)2,λ(rk,k)=(rk)!((1)r,λ)kk!(r!)k.

    We define the degenerate r-truncated Bell polynomials as

    ex(eλ(t)r1l=0(1)l,λl!tl)=n=0ϕ(r)n,λ(x)tnn!,(rN). (2.3)

    Thus, by (2.1) and (2.3), we have

    n=0ϕ(r)n,λ(x)tnn!=k=0xk1k!(eλ(t)r1l=0(1)l,λl!tl)k=k=0xkn=krS(r)2,λ(n,k)tnn!=n=0[nr]k=0xkS(r)2,λ(n,k)tnn!,

    where [x] denotes the greatest integer not exceeding x. Therefore, we obtain the following theorem.

    Theorem 1. For any integers n,r with n0,r1, we have

    ϕ(r)n,λ(x)=[nr]k=0xkS(r)2,λ(n,k).

    Now, we want to find a recursion formula for the degenerate r-truncated Stirling numbers of the second kind.

    Taking the derivative with respect to t on both sides of (2.1), we obtain

    n=kr1S(r)2,λ(n+1,k)tnn!=n=krS(r)2,λ(n,k)tn1(n1)!=ddt1k!(eλ(t)r1l=0(1)l,λl!tl)k. (2.4)

    Here we note that

    ddt1k!(eλ(t)r1l=0(1)l,λl!tl)k=kk!(eλ(t)r1l=0(1)l,λl!tl)k1(e1λλ(t)r1l=1(1)l,λl!ltl1)=1(k1)!(eλ(t)r1l=0(1)l,λl!tl)k1(eλ(t)(1+λt)r1l=1(1)l,λ(l1)!tl1)11+λt. (2.5)

    For the derivation of (2.6), we introduce the following notation

    Erλ,k1=1(k1)!(eλ(t)r1l=0(1)l,λl!tl)k1.

    Then, by (2.4) and (2.5), we get

    n=kr1{S(r)2,λ(n+1,k)+nλS(r)2,λ(n,k)}tnn!=(1+λt)n=kr1S(r)2,λ(n+1,k)tnn!=Erλ,k1(eλ(t)r2l=0(1)l+1,λl!tlλr1l=1(1)l,λ(l1)!tl)=Erλ,k1(eλ(t)r2l=0(1)l,λl!(1λl)tlλr1l=1(1)l,λ(l1)!tl)=Erλ,k1(eλ(t)r1l=0(1)l,λl!tl)+Erλ,k1(1(r1)!(1)r1,λtr1)+Erλ,k1(λr2l=0(1)l,λl!ltlλr1l=0(1)l,λl!ltl)=kk!(eλ(t)r1l=0(1)l,λl!tl)k+Erλ,k1((1)r1,λtr1(r1)!)λErλ,k1((1)r1,λ(r1)!(r1)tr1)=kn=krS(r)2,λ(n,k)tnn!+n=r(k1)S(r)2,λ(n,k1)tnn!(1)r1,λ(r1)!tr1λ(r1)(1)r1,λ(r1)!n=r(k1)S(r)2,λ(n,k1)tnn!tr1 (2.6)
    =n=kr1{kS(r)2,λ(n,k)+(1)r1,λ(nr1)S(r)2,λ(nr+1,k1)λ(r1)(1)r1,λ(nr1)S(r)2,λ(nr+1,k1)}tnn!.

    Comparing the coefficients on both sides of (2.6), we have the following theorem.

    Theorem 2. For n,k0 with nkr1, we have

    S(r)2,λ(n+1,k)=(knλ)S(r)2,λ(n,k)+(1)r1,λ(nr1)S(r)2,λ(nr+1,k1)λ(r1)(1)r1,λ(nr1)S(r)2,λ(nr+1,k1).

    Corollary 3. If r=1 in Theorem 2, then we have

    S(1)2,λ(n+1,k)=(knλ)S(1)2,λ(n,k)+S(1)2,λ(n,k1), (2.7)

    where n,k0 with nk1. So our result agrees with the fact in (1.9), as S(1)2,λ(n,k)=S2,λ(n,k).

    Now, we define the degenerate r-truncated Stirling numbers of the first kind as

    1k!(logλ(1+t)r1l=1(1)l,1/λλl1l!tl)k=n=krS(r)1,λ(n,k)tnn!, (2.8)

    where k is a nonnegative integer and r1.

    Taking the derivative with respect to t on both sides of (2.8), we get

    n=kr1S(r)1,λ(n+1,k)tnn!=n=krS(r)1,λ(n,k)tn1(n1)!=ddt1k!(logλ(1+t)r1l=1(1)l,1/λl!λl1tl)k. (2.9)

    Here we observe that

    ddt1k!(logλ(1+t)r1l=1(1)l,1/λl!λl1tl)k=kk!(logλ(1+t)r1l=1(1)l,1/λl!λl1tl)k1((1+t)λ1+tr1l=1(1)l,1/λ(l1)!λl1tl1). (2.10)

    For the derivation of (2.11), we introduce the following notation

    Lrλ,k1=1(k1)!(logλ(1+t)r1l=1(1)l,1/λl!λl1tl)k1.

    Then, by (2.9) and (2.10), we get

    n=kr1S(r)1,λ(n+1,k)tnn!(1+t)=Lrλ,k1((1+t)λr1l=1(1)l,1/λ(l1)!λl1tl1(1+t))=Lrλ,k1((1+t)λr2l=0(1)l+1,1/λl!λltlr1l=1(1)l,1/λl!lλl1tl)=Lrλ,k1((1+t)λr2l=0(1)l,1/λ(1lλ)λltll!r1l=1(1)l,1/λl!λl1ltl)=Lrλ,k1((1+t)λ1λr2l=1λl1(1)l,1/λl!tl+r2l=0(1)l,1/λλl1ltll!)Lrλ,k1(r1l=1(1)l,1/λl!λl1ltl)=λLrλ,k1(logλ(1+t)r1l=1(1)l,1/λl!λl1tl)+λr1(1)r1,1/λ(r1)!Lrλ,k1tr1(r1)(1)r1,1/λ(r1)!λr2Lrλ,k1tr1=kλn=krS(r)1,λ(n,k)tnn!+λr1(1)r1,1/λn=kr1(nr1)S(r)1,λ(nr+1,k1)tnn!(r1)(1)r1,1/λλr2n=kr1(nr1)S(r)1,λ(nr+1,k1)tnn!=n=kr1{kλS(r)1,λ(n,k)+λr1(1)r1,1/λ(nr1)S(r)1,λ(nr+1,k1)(r1)(1)r1,1/λλr2(nr1)S(r)1,λ(nr+1,k1)}tnn!. (2.11)

    On the other hand, by simple calculation, we get

    n=kr1S(r)1,λ(n+1,k)tnn!(1+t)=n=kr1S(r)1,λ(n+1,k)tnn!+n=krS(r)1,λ(n,k)ntnn!=n=kr1(S(r)1,λ(n+1,k)+nS(r)1,λ(n,k))tnn!. (2.12)

    From (2.11) and (2.12), we obtain the following theorem.

    Theorem 4. Let rN with r1. Then, for n,k0 with nkr1, we have

    S(r)1,λ(n+1,k)+nS(r)1,λ(n,k)=kλS(r)1,λ(n,k)+(λr+1)(1)r1,1/λλr2(nr1)S(r)1,λ(nr+1,k1).

    Corollary 5. If r=1 in Theorem 4, then we have

    S(1)1,λ(n+1,k)=(kλn)S(1)1,λ(n,k)+S(1)1,λ(n,k1), (2.13)

    where n,k0 with nk1. So our result agrees with the fact in (1.9), as S(1)1,λ(n,k)=S1,λ(n,k).

    In recent years, studying degenerate versions of some special numbers and polynomials have drawn the attention of many mathematicians with their regained interests, not only in combinatorial and arithmetical properties but also in applications to differential equations, identities of symmetry and probability theory.

    In this paper, we introduced the degenerate r-truncated Stirling numbers of the second kind and the first kind and derived their recurrence relations. They are degenerate versions of the r-truncated Stirling numbers of the second kind and the first kind, and reduce to the degenerate Stirling numbers of the second kind and the first kind for r=1.

    As one of our future research projects, we would like to continue to explore degenerate versions of some special numbers and polynomials and their applications to physics, science and engineering.

    The authors declare they have not used Artificial Intelligence (AI) tools in the creation of this article.

    This research was supported by the Daegu University Research Grant, 2023.

    The authors would like to thank the reviewers for their valuable comments and suggestions that helped improve the original manuscript in its present form.

    Taekyun Kim and Dae San Kim are the Guest Editors of special issue "Number theory, combinatorics and their applications: theory and computation" for AIMS Mathematics. Taekyun Kim and Dae San Kim were not involved in the editorial review and the decision to publish this article.



    [1] L. Carlitz, Degenerate Stirling, Bernoulli and Eulerian numbers, Utilitas Math., 15 (1979), 51–88.
    [2] L. Carlitz, A degenerate Staudt-Clausen theorem, Arch. Math. (Basel), 7 (1956), 28–33.
    [3] L. Comtet, Advanced Combinatorics: The Art of Finite and Infinite Expansions, New York: American Mathematical Society, 1974. https://doi.org/10.2307/2005450
    [4] H. Connamacher, J. Dobrosotskaya, On the uniformity of the approximation for r-associated Stirling numbers of the second kind, Contrib. Discrete Math., 15 (2020), 25–42.
    [5] U. Duran, M. Acikgoz, On degenerate truncated special polynomials, Mathematics, 8 (2020), 144. https://doi.org/10.3390/math8010144 doi: 10.3390/math8010144
    [6] R. Fray, A generating function associated with the generalized Stirling numbers, Fibonacci Quart., 5 (1967), 356–366.
    [7] F. T. Howard, Associated Stirling numbers, Fibonacci Quart., 18 (1980), 303–315.
    [8] F. T. Howard, Congruences for the Stirling numbers and associated Stirling numbers, Acta Arith., 55 (1990), 29–41.
    [9] D. S. Kim, T. Kim, A note on a new type of degenerate Bernoulli numbers, Russ. J. Math. Phys., 27 (2020), 227–235. https://doi.org/10.1134/S1061920820020090 doi: 10.1134/S1061920820020090
    [10] T. Kim, D. S. Kim, On some degenerate differential and degenerate difference operators, Russ. J. Math. Phys., 29 (2022), 37–46. https://doi.org/10.1134/S1061920822010046 doi: 10.1134/S1061920822010046
    [11] T. Kim, D. S. Kim, Some identities on truncated polynomials associated with degenerate Bell polynomials, Russ. J. Math. Phys., 28 (2021), 342–355. https://doi.org/10.1134/S1061920821030079 doi: 10.1134/S1061920821030079
    [12] T. Kim, D. S. Kim, L. C. Jang, H. Lee, H. Kim, Representations of degenerate Hermite polynomials, Adv. Appl. Math., 139 (2022), 102359. https://doi.org/10.1016/j.aam.2022.102359 doi: 10.1016/j.aam.2022.102359
    [13] T. Kim, D. S. Kim, H. K. Kim, Normal ordering of degenerate integral powers of number operator and its applications, Appl. Math. Sci. Eng., 30 (2022), 440–447. https://doi.org/10.1080/27690911.2022.2083120 doi: 10.1080/27690911.2022.2083120
    [14] T. Kim, D. S. Kim, Degenerate zero-truncated Poisson random variables, Russ. J. Math. Phys., 28 (2021), 66–72. https://doi.org/10.1134/S1061920821010076 doi: 10.1134/S1061920821010076
    [15] T. K. Kim, D. S. Kim, Some identities involving degenerate Stirling numbers associated with several degenerate polynomials and numbers, Russ. J. Math. Phys., 30 (2023), 62–75. https://doi.org/10.1134/S1061920823010041 doi: 10.1134/S1061920823010041
    [16] I. Kucukoglu, Y. Simsek, Construction and computation of unified Stirling-type numbers emerging from p-adic integrals and symmetric polynomials, Rev. Real Acad. Cienc. Exactas Fis. Nat. Ser. A-Mat., 115 (2021), 167. https://doi.org/10.1007/s13398-021-01107-2 doi: 10.1007/s13398-021-01107-2
    [17] D. H. Lehmer, Numbers associated with Stirling numbers and Number theory, Rocky Mountain J. Math., 15 (1985), 461–479.
    [18] S. Roman, The Umbral Calculus, Berlin: Springer, 2005.
    [19] B. Simsek, Some identities and formulas derived from analysis of distribution functions including Bernoulli polynomials and Stirling numbers, Filomat, 34 (2020), 521–527. https://doi.org/10.2298/FIL2002521S doi: 10.2298/FIL2002521S
    [20] Y. Simsek, Identities associated with generalized Stirling type numbers and Eulerian type polynomials, Math. Comput. Appl., 18 (2013), 251–263. https://doi.org/10.3390/mca18030251 doi: 10.3390/mca18030251
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