COMBINATORIAL CONVOLUTION SUMS DERIVED FROM DIVISOR FUNCTIONS AND FAULHABER SUMS

Similar documents
On the h-vector of a Lattice Path Matroid

SEMICENTRAL IDEMPOTENTS IN A RING

TWO-PERIODIC TERNARY RECURRENCES AND THEIR BINET-FORMULA 1. INTRODUCTION

A note on the number of (k, l)-sum-free sets

Some Bounds for the Singular Values of Matrices

Permutation Factorizations and Prime Parking Functions

The Sorting Index and Permutation Codes. Abstract

On the smallest abundant number not divisible by the first k primes

arxiv: v3 [math.nt] 10 Jul 2014

WEIGHTED SUM OF THE EXTENSIONS OF THE REPRESENTATIONS OF QUADRATIC FORMS

Existentially closed models of the theory of differential fields with a cyclic automorphism

GUESSING MODELS IMPLY THE SINGULAR CARDINAL HYPOTHESIS arxiv: v1 [math.lo] 25 Mar 2019

The Limiting Distribution for the Number of Symbol Comparisons Used by QuickSort is Nondegenerate (Extended Abstract)

Applied Mathematics Letters

A Property Equivalent to n-permutability for Infinite Groups

Lossy compression of permutations

Option Pricing Formula for Fuzzy Financial Market

HIGHER ORDER BINARY OPTIONS AND MULTIPLE-EXPIRY EXOTICS

Best-Reply Sets. Jonathan Weinstein Washington University in St. Louis. This version: May 2015

On the Number of Permutations Avoiding a Given Pattern

Chapter 4 Partial Fractions

Translates of (Anti) Fuzzy Submodules

DESCENDANTS IN HEAP ORDERED TREES OR A TRIUMPH OF COMPUTER ALGEBRA

BINOMIAL TRANSFORMS OF QUADRAPELL SEQUENCES AND QUADRAPELL MATRIX SEQUENCES

Local vs Non-local Forward Equations for Option Pricing

Markov Decision Processes II

Received May 27, 2009; accepted January 14, 2011

On the Distribution and Its Properties of the Sum of a Normal and a Doubly Truncated Normal

CONSTRUCTION OF CODES BY LATTICE VALUED FUZZY SETS. 1. Introduction. Novi Sad J. Math. Vol. 35, No. 2, 2005,

Palindromic Permutations and Generalized Smarandache Palindromic Permutations

Essays on Some Combinatorial Optimization Problems with Interval Data

The ruin probabilities of a multidimensional perturbed risk model

MATH3075/3975 FINANCIAL MATHEMATICS TUTORIAL PROBLEMS

Forecast Horizons for Production Planning with Stochastic Demand

On Machin s formula with Powers of the Golden Section

ON THE MAXIMUM AND MINIMUM SIZES OF A GRAPH

arxiv: v1 [math.co] 31 Mar 2009

ELEMENTS OF MONTE CARLO SIMULATION

Chapter 1 Additional Questions

Quadrant marked mesh patterns in 123-avoiding permutations

Probability. An intro for calculus students P= Figure 1: A normal integral

TWIST UNTANGLE AND RELATED KNOT GAMES

A NEW NOTION OF TRANSITIVE RELATIVE RETURN RATE AND ITS APPLICATIONS USING STOCHASTIC DIFFERENTIAL EQUATIONS. Burhaneddin İZGİ

Expected Value and Variance

BETA DISTRIBUTION ON ARITHMETICAL SEMIGROUPS

Research Article On the Classification of Lattices Over Q( 3) Which Are Even Unimodular Z-Lattices of Rank 32

ON THE MEAN VALUE OF THE SCBF FUNCTION

Cartesian Product of Two S-Valued Graphs

5.9: The Binomial Theorem

Notes on the symmetric group

EFFICIENT MONTE CARLO ALGORITHM FOR PRICING BARRIER OPTIONS

A THREE-FACTOR CONVERGENCE MODEL OF INTEREST RATES

A class of coherent risk measures based on one-sided moments

A No-Arbitrage Theorem for Uncertain Stock Model

Outline. 1 Introduction. 2 Algorithms. 3 Examples. Algorithm 1 General coordinate minimization framework. 1: Choose x 0 R n and set k 0.

Fuzzy L-Quotient Ideals

2.1 Random variable, density function, enumerative density function and distribution function

Yao s Minimax Principle

Chapter 8 Sequences, Series, and the Binomial Theorem

arxiv: v2 [math.lo] 13 Feb 2014

Sequences, Series, and Probability Part I

Math-Stat-491-Fall2014-Notes-V

Math 167: Mathematical Game Theory Instructor: Alpár R. Mészáros

American Option Pricing Formula for Uncertain Financial Market

More On λ κ closed sets in generalized topological spaces

On the Lower Arbitrage Bound of American Contingent Claims

Game-Theoretic Approach to Bank Loan Repayment. Andrzej Paliński

A relation on 132-avoiding permutation patterns

Lecture 5: Iterative Combinatorial Auctions

FURTHER ASPECTS OF GAMBLING WITH THE KELLY CRITERION. We consider two aspects of gambling with the Kelly criterion. First, we show that for

Laurence Boxer and Ismet KARACA

COMBINATORICS OF REDUCTIONS BETWEEN EQUIVALENCE RELATIONS

Estimation of Value at Risk and ruin probability for diffusion processes with jumps

Laurence Boxer and Ismet KARACA

OPTIMAL PORTFOLIO CONTROL WITH TRADING STRATEGIES OF FINITE

Theorem 1.3. Every finite lattice has a congruence-preserving embedding to a finite atomistic lattice.

University of California Berkeley

Factors of 10 = = 2 5 Possible pairs of factors:

CONGRUENCES AND IDEALS IN A DISTRIBUTIVE LATTICE WITH RESPECT TO A DERIVATION

A lower bound on seller revenue in single buyer monopoly auctions

Cumulants and triangles in Erdős-Rényi random graphs

An Optimal Odd Unimodular Lattice in Dimension 72

25 Increasing and Decreasing Functions

Best response cycles in perfect information games

THE IRREDUCIBILITY OF CERTAIN PURE-CYCLE HURWITZ SPACES

REMARKS ON K3 SURFACES WITH NON-SYMPLECTIC AUTOMORPHISMS OF ORDER 7

MAC Learning Objectives. Learning Objectives (Cont.)

THE USE OF NUMERAIRES IN MULTI-DIMENSIONAL BLACK- SCHOLES PARTIAL DIFFERENTIAL EQUATIONS. Hyong-chol O *, Yong-hwa Ro **, Ning Wan*** 1.

3.1 Properties of Binomial Coefficients

A note for hybrid Bollinger bands

SHORT-TIME IMPLIED VOLATILITY IN EXPONENTIAL LÉVY MODELS

On Complexity of Multistage Stochastic Programs

A RIDGE REGRESSION ESTIMATION APPROACH WHEN MULTICOLLINEARITY IS PRESENT

arxiv: v1 [math.lo] 27 Mar 2009

Optimizing Portfolios

Option Pricing under Delay Geometric Brownian Motion with Regime Switching

OPTION PRICE WHEN THE STOCK IS A SEMIMARTINGALE

Martingales. by D. Cox December 2, 2009

The Binomial Theorem and Consequences

KAPLANSKY'S PROBLEM ON VALUATION RINGS

Transcription:

GLASNIK MATEMATIČKI Vol. 49(69(014, 351 367 COMBINATORIAL CONVOLUTION SUMS DERIVED FROM DIVISOR FUNCTIONS AND FAULHABER SUMS Bumkyu Cho, Daeyeoul Kim and Ho Park Dongguk University-Seoul, National Institute for Mathematical Sciences, South Korea Abstract. It is known that certain convolution sums using Liouville identity can be expressed as a combination of divisor functions and Bernoulli numbers. In this article we find seven combinatorial convolution sums derived from divisor functions and Bernoulli numbers. 1. Introduction The symbols N, Z, Q and C denote the set of natural numbers, the ring of integers the field of rational numbers and the field of complex numbers, respectively. The Bernoulli polynomials B k (x, which are usually defined by the exponential generating function te xt e t 1 k0 B k (x tk k!, play an important role in different areas of mathematics including number theory and the theory of finite differences. The Bernoulli polynomials satisfy the following well-known identities : N k B k+1(n +1 B k+1 (0, (k 1 k +1 1 k +1 k ( k +1 ( 1 B N k+1. The Bernoulli numbers B k are defined to be B k : B k (0. 010 Mathematics Subect Classification. 33E0, 11A67. Key words and phrases. Divisor functions, convolution sums, Faulhaber s sum. 351

35 B. CHO, D. KIM AND H. PARK For n N, k Z 0, and l Q, we define some divisor functions: It is clear that σ k (n : d k, σ k(n : n d odd d k, σ # k (n : ( n d k, ˆσ k,l (n : σ k (n lσ k d N H k (N : k, Ĥ k,l (n : H k (n lh k (n/. ˆσ k,0 (n σ k (n, ˆσ k,1 (n σ k (n σ k(n σ k (n/, ˆσ k, k(n σ k (n, and Ĥ k,l (d 1 k +1 k ( k +1 ( 1 B ˆσ k+1,l (n. The identity n 1 σ(kσ(n k 5 ( 1 1 σ 3(n+ 1 1 n σ(n k1 for the basic convolution sum first appeared in a letter from Besge to Liouville in 186 (see []. For some of the history of the subect, and for a selection of these articles, we mention [3,9,10], and especially [5,11]. The study of convolution sums and their applications is classic and they play an important role in number theory. In this paper we are trying to focus on the combinatorial convolution sums. For positive integers k and n, the combinatorial convolution sum (1.1 k ˆσ k s 1,l (mˆσ,l (n m can be evaluated explicitly in terms of divisor functions and a sum of involving Faulhaber sums. We are motivated by Ramanuan s recursion formula for sums of the product of two Eisenstein series [1, Entry 14, p. 33] and its proof, and also the following propositions.

CONVOLUTION SUM 353 Proposition 1.1 ([11]. Let k, n be positive integers. Then k σ k s 1 (mσ (n m k +3 4k + σ k+1(n+ k+1 ( k 6 n σ (n k ( k+1 B σ k+1 (n, where B is the -th Bernoulli number. k r0 where and Proposition 1. ([4]. For any integers k 1 and N 3, we have ( k r [ N 1 ] i1 n 1 σ k r (m;i,nσ r (n m;i,n σ k+1 (n;n N nσ (n;n 1 N 1+( 1N [ N 1 ] (N iσ k (n;i,n i1 ( ( n σk+1 N ; N nσ σ r (n;i,n n d i(n d r ( 1 r ( n N ;, n d i(n σr (n;n d r σ r (n σ r (n/n. n d 0(N The aim of this article is to study seven combinatorial convolution sums of the analogous type (1.1. More precisely, we prove the following theorems and corollaries. Theorem 1.3. Let k,n be positive integers, and let l be a rational number. Then k ˆσ k s 1,l (mˆσ,l (n m (1. 1 ˆσ k+1, l +l(n 1 l ˆσ k,l(n n( l ˆσ,l (n+(1 l Ĥ k,l (d. d r

354 B. CHO, D. KIM AND H. PARK Remark 1.4. In Theorem 1.3, l 0 and l 1 recover Proposition 1.1 and Proposition., respectively. For k 1, we have the following corollary. Corollary 1.5. For any n N and l Q, we have n 1 ˆσ 1,l (mˆσ 1,l (n m 1 4ˆσ 3, l +l(n l 6 ˆσ 3,l(n+ 3n(l +1 l ˆσ 1,l (n. 1 Remark 1.6. In the preceding corollary, l recovers [7, (11]. Corollary 1.7. Let k, n be positive integers. Then k σ k s 1 (m/σ (n m 1 σ k+1(n/ 1 4ˆσ k, 1(n n 4ˆσ, (n Ĥ k, 1 (d. Corollary 1.8. Let k, n be positive integers. Then k σk s 1 (mσ (n m 1 σ k+1 (n 1 4 σ k (n 3n 4 ˆσ, (n Ĥ 3 k (d. Theorem 1.9. Let k,n be positive integers and let l be a rational number. Then k ˆσ k s 1,l (mˆσ,l (n m (1.3 1 l 4 ˆσ k+1,l 1(n 1 l ˆσ k,l(n n(1 lˆσ,l/ (n + l(σk+1 (n nσ (n+(1 l k,l (d Ĥ and (1.4 ( k n ˆσ k s 1,l (m 1ˆσ,l (n m+1 ˆσ 1 k+1,l(n+ l(l 1 σ k+1 (n+n(l ˆσ,l (n + l 1 4 ˆσ k+1,l 1(n n(l 1ˆσ,l/ (n l(σk+1(n nσ (n.

CONVOLUTION SUM 355 Remark 1.10. In (1.3, l 0 and l 1 recover Proposition.1 and Proposition., respectively. And in (1.4, l 0 recovers [8, Lemma 6.]. If we insert k 1 in the preceding theorem, one has the following corollary. and n Corollary 1.11. For n N and l Q we have n 1 ˆσ 1,l (mˆσ 1,l (n m 1 l 8 ˆσ 3,l 1(n l 6 ˆσ 3,l(n n(1 lˆσ 1,l/ (n l 1 ˆσ 1,l(n+l(σ 3 (n nσ 1 (n ˆσ 1,l (m 1ˆσ 1,l (n m+1 1 4ˆσ 3,l(n+ l(l 1 4 σ 3 (n+ n(l ˆσ 1,l (n + l 1 8 ˆσ 3,l 1(n n(l 1ˆσ 1,l/ (n l(σ3(n nσ 1(n. Theorem 1.1. Let k, n be positive integers. Then ( k n 1 k s 1 σ k s 1 (m/4σ (n m 1 4 σ k+1(n/ 1 4 (σ k(n k+1 σ k (n/ k σ k (n/4 n 4 (σ (n+ k σ (n/4 σ# k (n + k +1 + + k 1 (k +1 1 (k +1 1 (k +1 k where ( k+1 u,v,w (k+1! u!v!w!. ( k +1 B σ k+1 (n/ k ( k +1 ( k +1 u+v+wk+1 B k+1 σ k+1 (n/4 B σ # k+1 (n ( k +1 v 1 B v σ # u,v,w w(n.

356 B. CHO, D. KIM AND H. PARK Remark 1.13. In the preceding theorem, k 1 recovers [11, Theorem 15.].. Proofs of the theorems and corollaries To prove the theorems and corollaries, we need the following propositions. Proposition.1 ([8, Theorem 6.3]. Let k, n be positive integers. Then k σ k s 1 (mσ (n m k +3 4k + σ k+1(n 1 4 σ k+1(n+ k ( k +1 k +1 B σ k+1 (n. ( k 6 n σ (n Proposition. ([6, Identity (10]. Let k, n be positive integers. Then k σ k s 1(mσ (n m 1 (σ k+1(n nσ (n. Proposition.3 ([11, p.17]. Let n be a positive integer. Let f : Z C be an even function. Then (a,b,x,y N 4 4ax+byn (f(a b f(a+b 1 f(0(σ(n/ d(n/ d(n/4 1 df(d / /4 ( 1+ n f(d d ( 1+ n f(d d d l1 l d( f(l d /4 l1 f(l.

CONVOLUTION SUM 357 Proof of Theorem 1.3. Let k,n N and l Q. Then the left hand side is (.1 k ˆσ k s 1,l (mˆσ,l (n m ( k n 1 ( ( m σ k s 1 (m lσ k s 1 ( ( n m σ (n m lσ k ( σ k s 1 (mσ (n m ( m ( n m +l σ k σ k ( ( n m l σ k s 1 (mσ ( m +σ k σ (n m k ( ( m l σ k s 1 (m σ k s 1 ( ( n m σ (n m σ k ( +(1 l σ k s 1 (mσ (n m ( m ( n m lσ k s 1 σ. Now the first summation of the right side of (.1 becomes (. k ( ( m σ k s 1 (m σ k s 1 ( ( n m σ (n m σ k ( n m σk s 1 (mσ 1 (σ k+1 (n nσ (n

358 B. CHO, D. KIM AND H. PARK by Proposition.. Consider the second summation of the right side of (.1 by the use of Proposition 1.1. It equals (.3 k σ k s 1 (mσ (n m ( k +3 k 4k + σ k+1(n+ 6 n σ (n k +1 k ( k +1 B σ k+1 (n 1 σ k+1(n 1 σ k(n nσ (n k +1 k ( k +1 B σ k+1 (n 1 σ k+1(n 1 σ k(n nσ (n+ H k (d. Using Proposition 1.1, we observe that last summation of the right side of (.1 is (.4 k ( m σ k s 1 ( [ k n ] 1 k +3 n ( k k+1( 4k + σ + 6 n k ( k+1 k+1 1 ( n σ k+1 1 σ k k+1 1 σ k+1 k ( k+1 ( n 1 σ k σ ( n m σ k s 1 (mσ ( n m ( n σ ( n B σ k+1 ( n n ( n σ ( n B σ k+1 ( n n ( n σ + ( d H k.

CONVOLUTION SUM 359 Using (., (.3 and (.4, we get k ˆσ k s 1,l (mˆσ,l (n m l (σ k+1 (n nσ (n ( 1 +(1 l σ k+1(n 1 σ k(n nσ (n+ H k (d l(1 l( 1 σ k+1 ( n 1 ( n σ k n σ 1 σ k+1(n l( l ( n σ k+1 1 l + n(l ( ( n σ (n lσ ( n + ( d H k ( ( n σ k (n lσ k (l 1 Ĥ k,l (d 1 ˆσ k+1,l(n l(1 l ( n σ k+1 1 l ˆσ k,l(n n( l ˆσ,l (n+(1 l Ĥ k,l (d. Therefore the proof is completed. Proof of Corollary 1.7. We take l 1 in Theorem 1.3. Then the left hand side of Theorem 1.3 is k L (σ k s 1 (mσ (n m +σ k s 1 (m/σ ((n m/ k + (σ k s 1 (m/σ (n m +σ k s 1 (mσ ((n m/. Observing that replacing m and s by n m and k s respectively in L, k (σ k s 1 (m/σ (n m ( k n 1 m0 σ k s 1 (mσ ((n m/,

360 B. CHO, D. KIM AND H. PARK we find k L (σ k s 1 (mσ (n m +σ k s 1 (m/σ ((n m/ k + σ k s 1 (m/σ (n m. Consider the right hand side of Theorem 1.3. It it follows that 1 ˆσ k+1, 1(n+σ k+1 (n/ ˆσ k, 1 (n 3n ˆσ, 1(n+ Ĥ k, 1 (d. By Proposition 1.1 and Theorem 1.3, we deduce that k σ k s 1 (m/σ (n m 1 ˆσ k+1, 1(n+σ k+1 (n/ ˆσ k, 1 (n 3n ˆσ, 1(n + k Ĥ k, 1 (d (σ k s 1 (mσ (n m +σ k s 1 (m/σ ((n m/ 1 ˆσ k+1, 1(n+σ k+1 (n/ ˆσ k, 1 (n 3n ˆσ, 1(n + ( 1 Ĥ k, 1 (d σ k+1(n 1 σ k(n nσ (n+ H k (d σ k+1 ( n 1 ( n σ k n ( n σ + ( d H k σ k+1 (n/ 1 ˆσ k, 1(n n ˆσ, (n+ Ĥ k, 1 (d. This completes the proof. Proof of Corollary 1.8. Let k,n N. Then k σk s 1 (mσ (n m ( k n 1 ˆσ k s 1,1 (mσ (n m

CONVOLUTION SUM 361 k σ k s 1 (mσ (n m ( k n 1 σ k s 1 (m/σ (n m. Appealing to Corollary 1.7, we obtain k σk s 1 (mσ (n m 1 σ k+1(n 1 4 σ k(n n σ (n n 4 σ (n Ĥ k (d. Remark.4. Using Corollary 1.7, Corollary 1.8 and Proposition., we deduce k ˆσ k s 1, (mσ (n m for n odd. ( k n 1 σ k s 1 (mσ (n m Proof of Theorem 1.9. Let k,n N and l Q. The left hand side of Theorem 1.9 is equal to k ˆσ k s 1,l (mˆσ,l (n m k (σ k s 1 (mσ (n m +l σ k s 1 (mσ (n m k l (σ k s 1 (mσ (n m +σ k s 1 (mσ (n m k (1 l (σ k s 1 (mσ (n m lσ k s 1 (mσ (n m

36 B. CHO, D. KIM AND H. PARK k +l (σ k s 1 (m σ k s 1 (m (σ (n m σ (n m k (1 l (σ k s 1 (mσ (n m lσ k s 1 (mσ (n m k +l σk s 1 (mσ (n m. We can divide it into three parts: (.5 (.6 (.7 k σ k s 1 (mσ (n m, k σ k s 1 (mσ (n m, ( k n 1 σ k s 1 (mσ (n m. By making use of Proposition.1, (.5 can be written as k σ k s 1 (mσ (n m k +3 4k + σ k+1(n 1 ( k 4 σ k+1 (n+ 6 n k +1 k ( k +1 B σ k+1 (n σ (n 1 σ k+1(n 1 4 σ k+1 (n 1 σ k(n nσ (n+ H k (d.

CONVOLUTION SUM 363 Also, by Proposition 1.1, (.6 equals k σ k s 1 (mσ (n m ( k +3 k 4k + σ k+1(n+ 6 n σ (n k +1 k ( k +1 B σ k+1 (n 1 σ k+1(n 1 σ k(n nσ (n+ H k (d. By Proposition., (.7 is k σk s 1 (mσ (n m k Therefore, we obtain ( k n 1 (σ k+1 (n nσ (n. σ k s 1 (mσ (n m k ˆσ k s 1,l (mˆσ,l (n m 1 (1 l( σ k+1(n 1 4 σ k+1 (n 1 σ k(n nσ (n+ H k (d ( 1 l(1 l σ k+1(n 1 σ k(n nσ (n+ H k (d + l(σ k+1 (n nσ (n 1 l 4 ˆσ k+1,l 1(n 1 l ˆσ k,l(n n(1 lˆσ,l/ (n ( + l(σk+1 (n nσ (n+(1 l H k (d. H k (d l This proves (1.3 of Theorem 1.9. Using (1. and (1.3, we get (1.4. Therefore, the proof is completed.

364 B. CHO, D. KIM AND H. PARK Proof of Theorem 1.1. Following the technique used in [11], we take f(x x k in Proposition.3. Then the left hand side of Proposition.3 is ((a b k (a+b k (a,b,x,y N 4 4ax+byn (a,b,x,y N 4 4ax+byn k ( k ( k ( ( 1 s (a k s b s (a k s b s s k (a,b,x,y N 4 4ax+byn 4a m ((a k s 1 b (a k s 1 b n m b k k s 1 σ k s 1 (m/4σ (n m The right hand side of Proposition.3 is 1 (1+n/dd k 1 d k+1 (1+n/d(d k d x1 x d( / x k d /4x1 x k. /4 Set S 1 1 (1+n/dd k 1 d k+1 (1+n/d(d k S S 3 d x1 x d( d /4x1 x k x k. / /4 By the definition of divisor functions, we see that (.8 S 1 1 σ k+1(n/ (σ k(n+ k σ k (n/4 + n (σ (n+ k σ (n/4.

CONVOLUTION SUM 365 Next, we consider (.9 and (.10 (.11 S / d x1 x d( k k +1 k k +1 d d d x k d d/ x1 k x k + d k ( k +1 k +1 k k k +1 d k k 1 k+1 k d ( k +1 k x1(x k + d d (x 1 k d+1 x1 x1x k k d d+1 1 x k x1 B σ k+1 (n/+ k σ k (n/ B σ # k+1 (n+σ# k (n ( k +1 ( d+1 B ( k+1 ( d+1 B 1 k +1 k+1 i0 ( k +1 1 k +1 u+v+wk+1 k+1 B (d+1 k+1 k+1 ( ( k +1 k +1 ( k +1 v 1 B v σ w # u,v,w (n i B d k+1 i Similarly, from (.9 and (.10, we obtain k ( S k k +1 B σ k+1 (n/+ k σ k (n/ k +1 k +1 1 k +1 k ( k +1 u+v+wk+1 B σ # k+1 (n+σ# k (n ( k +1 v 1 B v σ w # u,v,w (n.

366 B. CHO, D. KIM AND H. PARK Finally, the equation S 3 is equivalent to (.1 S 3 d 1 /4 x1 k 1 k +1 x k + (d k /4 ( k +1 B k+1 σ k+1 (n/4+ k σ k (n/4. Hence, by (.8, (.11 and (.1, we obtain 1 σ k+1(n/ (σ k(n+ k σ k (n/4 + n (σ (n+ k σ (n/4 k k +1 1 k +1 k +1 1 k +1 k k ( k +1 B σ k+1 (n/ k σ k (n/ ( k +1 u+v+wk+1 k ( k +1 B σ # k+1 (n σ# k (n ( k +1 v 1 B v σ # u,v,w w(n B k+1 σ k+1 (n/4 k σ k (n/4 1 σ k+1(n/ (σ k(n k+1 σ k (n/ k σ k (n/4 + n (σ (n+ k σ (n/4 σ # k (n k k +1 1 k +1 1 k +1 k +1 k k k ( k +1 B σ k+1 (n/ ( k +1 ( k +1 u+v+wk+1 B k+1 σ k+1 (n/4 B σ # k+1 (n ( k +1 v 1 B v σ w # u,v,w (n.

CONVOLUTION SUM 367 Acknowledgements. The first author was supported by the Dongguk University Research Fund of 013 and the corresponding author was supported by the National Institute for Mathematical Sciences (NIMS grant funded by the Korean government (B1403. References [1] B. C. Berndt, Ramanuan s notebooks. Part II, Springer, 1989. [] Nesge, Extrait d une Lettre de M. Besge à M. Liouville, Journal de mathématiques et appliquées e série 7 (186, 56. [3] N. Cheng and K. S. Williams, Evaluation of some convolution sums involving the sum of divisors functions, Yokohama Math. J. 5 (005, 39 57. [4] B. Cho, D. Kim, and H. Park, Evaluation of a certain combinatorial convolution sum in higher level cases, J. Math. Anal. Appl. 406 (013, 03 10. [5] J. G. Huard, Z. M. Ou, B. K. Spearman, and K. S. Williams, Elementary evaluation of certain convolution sums involving divisor functions, in: Number theory for the millennium, II, A K Peters, Natick, 00, 9 74. [6] D. Kim and A. Bayad, Convolution identities for twisted Eisenstein series and twisted divisor functions, Fixed Point Theory Appl. 013, 013:81, 3 pp. [7] D.Kim,A.Kim,and Y.Li,Convolution sums arising from divisor functions, J.Korean Math. Soc. 50 (013, 331 360. [8] D. Kim, A. Kim and A. Sankaranarayanan, Bernoulli numbers, convolution sums and congruences of coefficients for certain generating functions, J. Inequal. Appl. 013, 013:5 6 pp. [9] D. B. Lahiri, On Ramanuan s function τ(n and the divisor function σ k (n. I, Bull. Calcutta Math. Soc. 38 (1946, 193 06. [10] G. Melfi, On some modular identities, in: Number theory, de Gruyter, Berlin, 1998, 371 38. [11] K. S. Williams, Number theory in the spirit of Liouville, Cambridge University Press, 011. B. Cho Department of Mathematics Dongguk University-Seoul 6 Pil-dong 3-ga Jung-gu Seoul South Korea E-mail: bam@dongguk.edu D. Kim National Institute for Mathematical Science Yuseong-daero 1689-gil Daeeon 305-811 South Korea E-mail: daeyeoul@nims.re.kr H. Park Department of Mathematics Dongguk University-Seoul, 6 Pil-dong 3-ga Jung-gu Seoul South Korea E-mail: ph140@dongguk.edu Received: 9.7.013.