HeandWangAdvancesinDifferenceEquations2012,2012:209 http://www.advancesindifferenceequations.com/content/2012/1/209 RESEARCH OpenAccess Recurrence formulae for Apostol-Bernoulli and Apostol-Euler polynomials YuanHe*andChunpingWang *Correspondence: [email protected] Abstract FacultyofScience,Kunming Inthispaper,usinggeneratingfunctionsandcombinatorialtechniques,weextend UniversityofScienceand Technology,Kunming,Yunnan AgohandDilcher’squadraticrecurrenceformulaforBernoullinumbersin(Agohand 650500,People’sRepublicofChina DilcherinJ.NumberTheory124:105-122,2007)toApostol-Bernoulliand Apostol-Eulerpolynomialsandnumbers. MSC: 11B68;05A19 Keywords: Apostol-Bernoullipolynomialsandnumbers;Apostol-Eulerpolynomials andnumbers;recurrenceformula 1 Introduction TheclassicalBernoullipolynomialsB (x)andEulerpolynomialsE (x)haveplayedimpor- n n tantrolesinmanybranchesofmathematicssuchasnumbertheory,combinatorics,special functionsandanalysis,andtheyareusuallydefinedbymeansofthefollowinggenerating functions: text (cid:2)∞ tn (cid:3) (cid:4) ext (cid:2)∞ tn (cid:3) (cid:4) = B (x) |t|<π , = E (x) |t|<π . (.) et– n n! et+ n n! n= n= Inparticular,B =B ()andE =nE (/)arecalledtheclassicalBernoullinumbersand n n n n Eulernumbers,respectively.Numerousinterestingpropertiesforthesepolynomialsand numbershavebeenexplored;see,forexample,[–]. Recently,usingsomerelationshipsinvolvingBernoullinumbers,AgohandDilcher[] extendedEuler’swell-knownquadraticrecurrenceformulaontheclassicalBernoullinum- bers (cid:5) (cid:6) (cid:2)n n (B +B )n= BB =–nB –(n–)B (n≥) (.) i n–i n– n i i= toobtainanexplicitexpressionfor(B +B )n witharbitrarynon-negativeintegersk,m, k m nandkandmnotbothzeroasfollows: (cid:5) (cid:6) (cid:2)n n (B +B )n= B B k m k+i m+n–i i i= k!m!(n+δ(k,m)(m+k+)) =– B m+n+k (m+k+)! ©2012HeandWang;licenseeSpringer.ThisisanOpenAccessarticledistributedunderthetermsoftheCreativeCommons AttributionLicense(http://creativecommons.org/licenses/by/2.0),whichpermitsunrestricteduse,distribution,andreproduction inanymedium,providedtheoriginalworkisproperlycited. HeandWangAdvancesinDifferenceEquations2012,2012:209 Page2of16 http://www.advancesindifferenceequations.com/content/2012/1/209 (cid:7) (cid:5) (cid:6)(cid:5) (cid:6) (cid:2)m+k B k+ k+–i im + (–)i m+k+–i (–)k n– m+k+–i i k+ k+ i= (cid:5) (cid:6)(cid:5) (cid:6)(cid:8) m+ m+–i ik +(–)m n– B , (.) n+i– i m+ m+ whereδ(k,m)=whenk=orm=,andδ(k,m)=otherwise.Asfurtherapplications, Agoh and Dilcher [] derived some new types of recurrence formulae on the classical BernoullinumbersandshowedthatthevaluesofB dependonlyonB ,B ,...,B n n n+ n forapositiveintegernand,similarly,forB andB . n+ n+ Inthispaper,usinggeneratingfunctionsandcombinatorialtechniques,weextendthe abovementionedAgohandDilcherquadraticrecurrenceformulaforBernoullinumbers toApostol-BernoulliandApostol-Eulerpolynomialsandnumbers.Theseresultsalsolead to some known ones related to the formulae on products of the classical Bernoulli and EulerpolynomialsandnumbersstatedinNielsen’sclassicalbook[]. 2 Preliminariesandknownresults WefirstrecalltheApostol-BernoullipolynomialswhichwereintroducedbyApostol[] (seealsoSrivastava[]forasystematicstudy)inordertoevaluatethevalueoftheHurwitz- Lerchzetafunction.Forsimplicity,weherestartwiththeApostol-Bernoullipolynomials B(α)(x;λ)of(realorcomplex)orderαgivenbyLuoandSrivastava[] n (cid:5) (cid:6) t α (cid:2)∞ tn (cid:3) (cid:4) ext= B(α)(x;λ) |t+logλ|<π;α:= . (.) λet– n n! n= Especiallythecase α= in(.)givestheApostol-Bernoullipolynomialswhicharede- notedbyB (x;λ)=B()(x;λ).Moreover,B (λ)=B (;λ)arecalledtheApostol-Bernoulli n n n n numbers.Further,Luo[]introducedtheApostol-EulerpolynomialsE(α)(x;λ)oforderα: n (cid:5) (cid:6) α (cid:2)∞ tn (cid:3) (cid:4) ext= E(α)(x;λ) |t+logλ|<π;α:= . (.) λet+ n n! n= The Apostol-Euler polynomials E (x;λ) and Apostol-Euler numbers E (λ) are given by n n E (x;λ)=E()(x;λ) and E (λ)=nE (/;λ),respectively.Obviously, B (x;λ) and E (x;λ) n n n n n n reducetoB (x)andE (x)whenλ=.SeveralinterestingpropertiesforApostol-Bernoulli n n andApostol-Eulerpolynomialsandnumbershavebeenpresentedin[–].Nextwegive somebasicpropertiesforApostol-BernoulliandApostol-Eulerpolynomialsoforderαas statedin[,]. Proposition. DifferentialrelationsoftheApostol-BernoulliandApostol-Eulerpolyno- mialsoforderα:fornon-negativeintegerskandnwith≤k≤n, ∂k (cid:9) (cid:10) n!B(α)(x;λ) ∂k (cid:9) (cid:10) n!E(α)(x;λ) B(α)(x;λ) = n–k , E(α)(x;λ) = n–k . (.) ∂xk n (n–k)! ∂xk n (n–k)! Proposition. DifferenceequationsoftheApostol-BernoulliandApostol-Eulerpolyno- mialsoforderα:forapositiveintegern, (cid:3) (cid:4) λB(α)(x+;λ)–B(α)(x;λ)=nB(α–)(x;λ) B()(x;λ)=xn , (.) n n n– n HeandWangAdvancesinDifferenceEquations2012,2012:209 Page3of16 http://www.advancesindifferenceequations.com/content/2012/1/209 and (cid:3) (cid:4) λE(α)(x+;λ)+E(α)(x;λ)=E(α–)(x;λ) E()(x;λ)=xn . (.) n n n n Proposition. AdditiontheoremsoftheApostol-BernoulliandApostol-Eulerpolynomi- alsoforderα:forasuitableparameterβ andanon-negativeintegern, (cid:5) (cid:6) (cid:2)n (cid:3) (cid:4) n B(α+β)(x+y;λ)= B(α)(x;λ)B(β)(y;λ) B()(x;λ)=xn , (.) n i i n–i n i= and (cid:5) (cid:6) (cid:2)n (cid:3) (cid:4) n E(α+β)(x+y;λ)= E(α)(x;λ)E(β)(y;λ) E()(x;λ)=xn . (.) n i i n–i n i= Proposition. ComplementaryadditiontheoremsoftheApostol-BernoulliandApostol- Eulerpolynomialsoforderα:foranon-negativeintegern, (–)n (cid:3) (cid:4) (–)n (cid:3) (cid:4) B(α)(α–x;λ)= B(α) x;λ– , E(α)(α–x;λ)= E(α) x;λ– . (.) n λα n n λα n Settingα=,β=andα=λ=,β=intheformulae(.)to(.),weimmediately getthecorrespondingformulaefortheApostol-BernoulliandApostol-Eulerpolynomials, andtheclassicalBernoulliandEulerpolynomials,respectively.Itisworthnotingthatthe casesα=λ=inProposition.arealsocalledthesymmetricdistributionsoftheclas- sicalBernoulliandEulerpolynomials.Theabovepropositionswillbeveryusefultoin- vestigatethequadraticrecurrenceformulaefortheApostol-BernoulliandApostol-Euler polynomialsinthenexttwosections. 3 RecurrenceformulaeforApostol-Bernoullipolynomials Inwhatfollows,weshallalwaysdenotebyδ theKroneckersymbolwhichisdefinedby ,λ δ =oraccordingtoλ(cid:5)=orλ=,andalsodenoteB (x;λ)=E (x;λ)=foranypos- ,λ –n –n itiveintegern.BeforestatingthequadraticrecurrenceformulafortheApostol-Bernoulli polynomials,webeginwithasummationformulaconcerningthequadraticrecurrenceof theApostol-Bernoullipolynomials. Theorem. Letk,m,nbenon-negativeintegers.Then (cid:5) (cid:6) (cid:2)n (cid:3) (cid:4) n B(x;μ)+B (y;λμ) k i m+n–i i i= n+k =–δ B (x+y;λμ) ,λ m+n+k m+ n+k +B (y;λ)B (x+y;μ)+ B (y;λ)B (x+y;μ) m n+k m+ n+k– m+ (cid:5) (cid:6) (cid:2)m m B (x;λ–) +(n+k) (–)m+iB (x+y;λμ) m+–i . (.) n+k+i– i m+–i i= HeandWangAdvancesinDifferenceEquations2012,2012:209 Page4of16 http://www.advancesindifferenceequations.com/content/2012/1/209 Proof Multiplyingbothsidesoftheidentity (cid:5) (cid:6) λeu = + (.) λeu–μev– λeu– μev– λμeu+v– byv(u+v)exv+y(u+v)yields vexv (u+v)ey(u+v) eyu ve(x+y)v e(–x)u (u+v)e(x+y)(u+v) =(u+v) –λv . (.) μev– λμeu+v– λeu–μev– λeu– λμeu+v– Makingk-timesderivativefortheaboveidentity(.)withrespecttov,withthehelpof theLeibnizrule,weobtain (cid:5) (cid:6) (cid:5) (cid:6) (cid:5) (cid:6) (cid:2)k k ∂j vexv ∂k–j (u+v)ey(u+v) j ∂vj μev– ∂vk–j λμeu+v– j= (cid:5) (cid:6) (cid:5) (cid:6) (cid:5) (cid:6) ueyu ∂k ve(x+y)v eyu ∂k ve(x+y)v eyu ∂k– ve(x+y)v = +v +k λeu–∂vk μev– λeu–∂vk μev– λeu–∂vk– μev– (cid:5) (cid:6) (cid:5) (cid:6) e(–x)u ∂k (u+v)e(x+y)(u+v) e(–x)u ∂k– (u+v)e(x+y)(u+v) –λv –λk . (.) λeu–∂vk λμeu+v– λeu–∂vk– λμeu+v– Since B (x;λ)= when λ= and B (x;λ)= when λ(cid:5)= (see, e.g., []), so by setting B (x;λ)=δ ,weget ,λ exu δ (cid:2)∞ B (x;λ)um ,λ m+ – = . (.) λeu– u m+ m! m= Ontheotherhand,byTaylor’stheorem,wehave (cid:5) (cid:6) (cid:2)∞ (cid:2)∞ (cid:2)∞ (u+v)ex(u+v) ∂n uexu vn umvn = = B (x;λ) . (.) λeu+v– ∂un λeu– n! m+n m! n! n= m=n= Applying(.),(.)and(.)to(.),inviewoftheCauchyproductandthecomplemen- taryadditiontheoremoftheApostol-Bernoullipolynomials,wederive (cid:11) (cid:5) (cid:6) (cid:5) (cid:6) (cid:12) (cid:2)∞ (cid:2)∞ (cid:2)n n (cid:2)k k umvn B (x;μ)B (y;λμ) i+j m+n+k–i–j i j m! n! m=n= i= j= (cid:13) (cid:14) (cid:2)∞ (cid:2)∞ kB (y;λ)B (x+y;μ) umvn = B (y;λ)B (x+y;μ)+ m+ n+k– m n+k m+ m! n! m=n= (cid:2)∞ (cid:2)∞ B (y;λ)B (x+y;μ)umvn+ kδ (cid:2)∞ vn + m+ n+k + ,λ B (x+y;μ) n+k– m+ m! n! u n! m=n= n= (cid:2)∞ (cid:2)∞ (cid:2)∞ δ vn+ um–vn+ + ,λ B (x+y;μ) –δ B (x+y;λμ) n+k ,λ m+n+k u n! m! n! n= m=n= (cid:11) (cid:5) (cid:6) (cid:12) (cid:2)∞ (cid:2)∞ (cid:2)m m B (x;λ–) umvn+ + (–)m+iB (x+y;λμ) m+–i n+k+i i m+–i m! n! m=n= i= HeandWangAdvancesinDifferenceEquations2012,2012:209 Page5of16 http://www.advancesindifferenceequations.com/content/2012/1/209 (cid:11) (cid:5) (cid:6) (cid:12) (cid:2)∞ (cid:2)∞ (cid:2)m m B (x;λ–) umvn +k (–)m+iB (x+y;λμ) m+–i n+k+i– i m+–i m! n! m=n= i= (cid:2)∞ (cid:2)∞ um–vn –kδ B (x+y;λμ) . (.) ,λ m+n+k– m! n! m=n= Comparing the coefficients of umvn+/m!(n + )! and um/m! in (.), we conclude our proof. (cid:2) AsaspecialcaseofTheorem.,wehavethefollowing Corollary. Letmandnbepositiveintegers.Then (cid:5) (cid:6) (cid:2)m (cid:3) (cid:4) m (–)m–iB y–x;λ– B (y;λμ)– B (x;λ)B (y;μ) m–i n+i– m n– m i m i= (cid:5) (cid:6) (cid:2)n n =– B (y–x;μ)B (x;λμ)+ B (x;λ)B (y;μ). (.) n–i m+i– m– n n i n i= Proof Settingk=andsubstitutingyforxandxforyinTheorem.,weobtainthatfor non-negativeintegersmandn,wehave (cid:5) (cid:6) (cid:2)n n B (y;μ)B (x;λμ) n–i m+i i i= n =B (x;λ)B (x+y;μ)+ B (x;λ)B (x+y;μ) m n m+ n– m+ (cid:5) (cid:6) (cid:2)m+ (cid:3) (cid:4) n m+ + (–)m+iB y;λ– B (x+y;λμ). (.) m+–i n+i– m+ i i= Hence,replacingybyy–xintheabovegivesthedesiredresult. (cid:2) Remark. Settingλ=μ=,x=tandy=–tinCorollary.,byB (–x)=(–)nB (x) n n foranon-negativeintegern,weimmediatelygetthegeneralizationofWoodcock’sidentity ontheclassicalBernoullinumbers,see[,], (cid:5) (cid:6) (cid:2)m m (–)iB (t)B (t)– B (t)B (t) m–i n+i– m n– m i m i= (cid:5) (cid:6) (cid:2)n n = (–)iB (t)B (t)– B (t)B (t) (m,n≥). (.) n–i m+i– n m– n i n i= Applying the difference equation and symmetric distribution of the classical Bernoulli polynomials, one can get (–)nB (–x)=B (x)+nxn– for a positive integer n. Combin- n n ingwithCorollary.,wehaveanothersymmetricexpressionontheclassicalBernoulli numbersduetoAgoh,see[,], (cid:5) (cid:6) (cid:5) (cid:6) (cid:2)m (cid:2)n m n B B + B B =–B (m,n≥). (.) m–i n+i– n–i m+i– m+n– m i n i i= i= HeandWangAdvancesinDifferenceEquations2012,2012:209 Page6of16 http://www.advancesindifferenceequations.com/content/2012/1/209 Using Theorem ., we shall give the following quadratic recurrence formula for Apostol-Bernoullipolynomials. Theorem. Letk,m,nbenon-negativeintegers.Then (cid:3) (cid:4) B (x;μ)+B (y;λμ) n k m k!m!(n+δ(k,m)(m+k+)) =–δ B (x+y;λμ) ,λ m+n+k (m+k+)! (cid:7) (cid:5) (cid:6) (cid:5) (cid:6)(cid:8) (cid:2)m+k m m B (x;λ–) + (–)m+i n –k B (x+y;λμ) m+k+–i n+i– i i– m+k+–i i= (cid:7) (cid:5) (cid:6) (cid:5) (cid:6)(cid:8) (cid:2)m+k k k B (y;λ) + (–)k+i n –m B (x+y;μ) m+k+–i , (.) n+i– i i– m+k+–i i= where δ(k,m)=– when k =m=, δ(k,m)= when k =, m≥ or m=, k ≥, and δ(k,m)=otherwise. Proof Settingk=andsubstitutingm+kforminTheorem.,wehave (cid:3) (cid:4) B (x;μ)+B (y;λμ) n m+k nB (x+y;λμ) =–δ m+n+k +B (y;λ)B (x+y;μ) ,λ m+k n m+k+ (cid:5) (cid:6) nB (y;λ)B (x+y;μ) (cid:2)m+k m+k + m+k+ n– +n (–)m+k+i m+k+ i i= B (x;λ–) ×B (x+y;λμ) m+k+–i , (.) n+i– m+k+–i whichisjustthecaseδ(k,m)=–orinTheorem..Next,considerthecaseδ(k,m)=. WeshalluseinductiononkinTheorem.toproveTheorem..Clearly,thecasek= inTheorem.gives (cid:3) (cid:4) (cid:3) (cid:4) B (x;μ)+B (y;λμ) n+ B (x;μ)+B (y;λμ) n m m+ n+ =–δ B (x+y;λμ) ,λ m+n+ m+ n+ +B (y;λ)B (x+y;μ)+ B (y;λ)B (x+y;μ) m n+ m+ n m+ (cid:5) (cid:6) (cid:2)m m B (x;λ–) +(n+) (–)m+iB (x+y;λμ) m+–i . (.) n+i i m+–i i= Notingthatforanynon-negativeintegerk, (cid:5) (cid:6) (cid:2)m m B (x;λ–) (–)m+iB (x+y;λμ) m+–i n+k+i– i m+–i i= (cid:5) (cid:6) (cid:2)m+k m B (x;λ–) = (–)m+k+iB (x+y;λμ) m+k+–i . (.) n+i– i–k m+k+–i i= HeandWangAdvancesinDifferenceEquations2012,2012:209 Page7of16 http://www.advancesindifferenceequations.com/content/2012/1/209 Hence,substituting(.)and(.)to(.),wegetthecasek=ofTheorem..Now assumethatTheorem.holdsforallpositiveintegersbeinglessthank.From(.)and (.),weobtain (cid:3) (cid:4) B (x;μ)+B (y;λμ) n k m (n+k)B (x+y;λμ) =–δ m+n+k ,λ m+ (n+k)B (y;λ)B (x+y;μ) +B (y;λ)B (x+y;μ)+ m+ n+k– m n+k m+ (cid:5) (cid:6) (cid:2)m+k m B (x;λ–) +(n+k) (–)m+k+iB (x+y;λμ) m+k+–i n+i– i–k m+k+–i i= (cid:5) (cid:6) (cid:3) (cid:4) (cid:2)k– (cid:3) (cid:4) k – B (x;μ)+B (y;λμ) n– B(x;μ)+B (y;λμ) n. (.) m+k j m+k–j j j= Since(.)holdsforallpositiveintegersbeinglessthank,wehave (cid:5) (cid:6) (cid:2)k– (cid:3) (cid:4) k B(x;μ)+B (y;λμ) n j m+k–j j j= (cid:3) (cid:4) (cid:5) (cid:6) (m+n+k+)B (x+y;λμ)(cid:2)k– k (cid:2)m+k (cid:2)k– k =–δ m+n+k (cid:3) j (cid:4) + (–)m+i ,λ m+k+ m+k j j= j i= j= (cid:7) (cid:5) (cid:6) (cid:5) (cid:6)(cid:8) m+k–j m+k–j B (x;λ–) ×(–)k–j n –j B (x+y;λμ) m+k+–i n+i– i i– m+k+–i (cid:5) (cid:6) (cid:7) (cid:5)(cid:6) (cid:5) (cid:6)(cid:8) (cid:2)m+k (cid:2)k– k j j + (–)k+i (–)k–j n –(m+k–j) j i i– i= j= B (y;λ) ×B (x+y;μ) m+k+–i . (.) n+i– m+k+–i Foranynon-negativeintegersi,k,m, (cid:3) (cid:4) (cid:2)k k m+k+ (cid:3) j (cid:4) = , m+k m+ j= j (.) (cid:5) (cid:6)(cid:5) (cid:6) (cid:5) (cid:6) (cid:2)k k m+j m (–)j =(–)k . j i i–k j= Itfollowsfrom(.)that (cid:3) (cid:4) (cid:2)k– k k k!m! (cid:3) j (cid:4) = – , (.) m+k m+ (m+k)! j= j (cid:5) (cid:6)(cid:5) (cid:6) (cid:7)(cid:5) (cid:6) (cid:5) (cid:6)(cid:8) (cid:5) (cid:6) (cid:2)k– k m+k–j m m+k m (–)k–j =(–)k – – , (.) j i i–k i i j= HeandWangAdvancesinDifferenceEquations2012,2012:209 Page8of16 http://www.advancesindifferenceequations.com/content/2012/1/209 (cid:5) (cid:6)(cid:5) (cid:6) (cid:5) (cid:6) (cid:5) (cid:6) (cid:2)k– k m+k–j m m (–)k–jj =(–)k–k –k , (.) j i– i–k i– j= (cid:5) (cid:6)(cid:5)(cid:6) (cid:5) (cid:6) (cid:5) (cid:6) (cid:5) (cid:6) (cid:2)k– k j k (–)k–j = –(–)k – , (.) j i i–k i i j= (cid:5) (cid:6)(cid:5) (cid:6) (cid:2)k– k j (–)k–j(m+k–j) j i– j= (cid:5) (cid:6) (cid:5) (cid:6) (cid:5) (cid:6) (cid:5) (cid:6) k =–m –(–)k(m+k) +m –k . (.) i– i– i–k– i–k Bysubstitutingtheaboveidentities(.)-(.)to(.),weget (cid:5) (cid:6) (cid:2)k– (cid:3) (cid:4) k B(x;μ)+B (y;λμ) n j m+k–j j j= (cid:5) (cid:6) (m+n+k+)B (x+y;λμ) k k!m! =–δ m+n+k – ,λ m+k+ m+ (m+k)! (cid:7) (cid:5) (cid:6) (cid:5) (cid:6) (cid:5) (cid:6) (cid:5) (cid:6)(cid:8) (cid:2)m+k m m m+k m – (–)m+i n –k +(–)kn –(–)k(n+k) i i– i i–k i= B (x;λ–) ×B (x+y;λμ) m+k+–i n+i– m+k+–i (cid:7) (cid:5) (cid:6) (cid:5) (cid:6)(cid:8) (cid:2)m+k k k B (y;λ) – (–)k+i n –m B (x+y;μ) m+k+–i n+i– i i– m+k+–i i= n+k nB (y;λ) + B (y;λ)B (x+y;μ)– m+k+ B (x+y;μ) m+ n+k– n– m+ m+k+ –B (y;λ)B (x+y;μ)+B (y;λ)B (x+y;μ). (.) m+k n m n+k Thus,putting(.)and(.)to(.)concludestheinductionstep.Thiscompletesthe proofofTheorem.. (cid:2) Obviously,thecasesλ=μ=andx=y=inTheorem.leadtotheAgoh-Dilcher quadraticrecurrenceformula(.).WenowuseTheorem.togivethefollowingformula onproductsoftheApostol-Bernoullipolynomials. Corollary. Letmandnbepositiveintegers.Then (cid:5) (cid:6) (cid:2)m m (cid:3) (cid:4)B (y;λμ) B (x;λ)B (y;μ)=n (–)m–iB y–x;λ– n+i m n m–i i n+i i= (cid:5) (cid:6) (cid:2)n n B (x;λμ) +m B (y–x;μ) m+i n–i i m+i i= m!n! –(–)mδ B (y–x;μ). (.) ,λμ m+n (m+n)! HeandWangAdvancesinDifferenceEquations2012,2012:209 Page9of16 http://www.advancesindifferenceequations.com/content/2012/1/209 Proof Takingn=andthensubstitutingmfork,nform,λforμandμforλinTheo- rem.,weobtainthatforpositiveintegersmandn, (cid:5) (cid:6) (cid:2)m m B (y;μ) B (x;λ)B (y;λμ)=n (–)iB (x+y;λ) n+i m n m–i i n+i i= (cid:5) (cid:6) (cid:2)n n B (x;μ–) +m (–)iB (x+y;λμ) m+i n–i i m+i i= δ m!n! – ,μ B (x+y;λμ). (.) m+n (m+n)! Substituting –y fory and μ– for λμ in(.)andusingthecomplementaryaddition theoremforApostol-Bernoullipolynomials,wegetourresult. (cid:2) Remark. Thecasesλ=μ=andx=yinCorollary.togetherwiththefactB =–/ andB =forapositiveintegern(see,e.g.,[])willyieldthatforpositiveintegersm n+ andn,see[,], [(cid:2)m+n](cid:7) (cid:5) (cid:6) (cid:5) (cid:6)(cid:8) m n B (x) m!n! B (x)B (x)= n +m B m+n–i +(–)m+ B , (.) m n i m+n i i m+n–i (m+n)! i= where[x]isthemaximumintegerlessthanorequaltotherealnumberx. 4 RecurrenceformulaeformixedApostol-BernoulliandApostol-Euler polynomials Inthissection,weshallusetheabovemethodstogivesomequadraticrecurrenceformu- laeformixedApostol-BernoulliandApostol-Eulerpolynomials.AsintheproofofTheo- rem.,weneedthefollowingsummationformulaconcerningthequadraticrecurrence ofmixedApostol-BernoulliandApostol-Eulerpolynomials. Theorem. Letk,m,nbenon-negativeintegers.Then (cid:5) (cid:6) (cid:2)n (cid:3) (cid:4) n E(x;μ)+B (y;λμ) k i m+n–i i i= (cid:5) (cid:6) (cid:2)m (cid:3) (cid:4) m = (–)m+iE x;λ– B (x+y;λμ) m–i n+k+i i i= (cid:9) (cid:10) – mE (y;λ)E (x+y;μ)+(n+k)E (y;λ)E (x+y;μ) . (.) m– n+k m n+k– Proof Multiplyingbothsidesoftheidentity (cid:5) (cid:6) λeu = – (.) λeu+μev+ λeu+ μev+ λμeu+v– by(u+v)exv+y(u+v),wehave exv (u+v)ey(u+v) e(–x)u(u+v)e(x+y)(u+v) u+v eyu e(x+y)v =λ – . (.) μev+ λμeu+v– λeu+ λμeu+v– λeu+μev+ HeandWangAdvancesinDifferenceEquations2012,2012:209 Page10of16 http://www.advancesindifferenceequations.com/content/2012/1/209 Makingk-timesderivativefortheaboveidentity(.)withrespecttov,withthehelpof theLeibnizrule,weget (cid:5) (cid:6) (cid:5) (cid:6) (cid:5) (cid:6) (cid:2)k k ∂j exv ∂k–j (u+v)ey(u+v) j ∂vj μev+ ∂vk–j λμeu+v– j= (cid:5) (cid:6) e(–x)u ∂k (u+v)e(x+y)(u+v) =λ λeu+∂vk λμeu+v– (cid:5) (cid:6) (cid:5) (cid:6) u+v eyu ∂k e(x+y)v k eyu ∂k– e(x+y)v – – . (.) λeu+∂vk μev+ λeu+∂vk– μev+ Applying(.)and(.)to(.),inviewoftheCauchyproductandthecomplementary additiontheoremfortheApostol-Eulerpolynomials,weobtain (cid:11) (cid:5) (cid:6) (cid:5) (cid:6) (cid:12) (cid:2)∞ (cid:2)∞ (cid:2)n n (cid:2)k k um vn E (x;μ)B (y;λμ) · i+j m+n+k–i–j i j m! n! m=n= i= j= (cid:11) (cid:5) (cid:6) (cid:12) (cid:2)∞ (cid:2)∞ (cid:2)m m (cid:3) (cid:4) umvn = (–)m+iE x;λ– B (x+y;λμ) m–i n+k+i i m! n! m=n= i= (cid:2)∞ (cid:2)∞ E (y;λ)E (x+y;μ)um+vn (cid:2)∞ (cid:2)∞ E (y;λ)E (x+y;μ)umvn+ m n+k m n+k – – m! n! m! n! m=n= m=n= (cid:2)∞ (cid:2)∞ k umvn – E (y;λ)E (x+y;μ) . (.) m n+k– m! n! m=n= Thus,bycomparingthecoefficientsofum+vn+/(m+)!(n+)!andum+/(m+)!in(.), wecompletetheproofofTheorem.. (cid:2) WenowgiveaspecialcaseofTheorem..Wehavethefollowing Corollary. Letmandnbepositiveintegers.Then (cid:5) (cid:6) (cid:2)m (cid:3) (cid:4) m m (–)m–iE y–x;λ– B (y;λμ)– E (x;λ)E (y;μ) m–i n+i m– n i i= (cid:5) (cid:6) (cid:2)n n n = E (y–x;μ)B (x;λμ)– E (y;μ)E (x;λ). (.) n–i m+i n– m i i= Proof Settingk=andsubstitutingyforxandxforyinTheorem.,weobtainthatfor positiveintegersmandn, (cid:5) (cid:6) (cid:2)n n E (y;μ)B (x;λμ) n–i m+i i i= (cid:5) (cid:6) (cid:2)m (cid:3) (cid:4) m = (–)m–iE y;λ– B (x+y;λμ) m–i n+i i i= (cid:9) (cid:10) – mE (x;λ)E (x+y;μ)+nE (x+y;μ)E (x;λ) . (.) m– n n– m Thus,replacingybyy–xintheabovegivesthedesiredresult. (cid:2)
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