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Further Generalizations of Happy Numbers
Further Generalizations of Happy Numbers E. S. Williams June 15, 2016 Abstract In this paper we generalize the concept of happy numbers in several ways. First we confirm known results of Grundman and Teeple in [2] and establish further results, not given in that work. Then we construct a similar function expanding the definition of happy numbers to negative integers. Using this function, we compute and prove results extending those regarding higher powers and sequences of consecutive happy numbers that El-Sidy and Siksek and Grundman and Teeple proved in [1], [2] and [3] to negative integers. Finally, we consider a variety of special cases, in which the existence of certain fixed points and cycles of infinite families of generalized happy functions can be proven. 1 Introduction Happy numbers have been studied for many years, although the origin of the concept is unclear. Consider the sum of the square of the digits of an arbitrary positive integer. If repeating the process of taking the sums of the squares of the digits of an integer eventually gets us 1, then that integer is happy. This paper first provides a brief overview of traditional happy numbers, then describes existing work on generalizations of the concept to other bases and higher powers. We extend some earlier results for the cubic case to the quartic case. We then extend the happy function S to negative integers, constructing a function Q : Z ! Z which agrees with S over Z+ for this purpose. We then generalize Q to various bases and higher powers. As is traditional in 1 the study of special numbers, we consider consecutive sequences of happy numbers, and generalize this study to Q. -
POWER FIBONACCI SEQUENCES 1. Introduction Let G Be a Bi-Infinite Integer Sequence Satisfying the Recurrence Relation G If
POWER FIBONACCI SEQUENCES JOSHUA IDE AND MARC S. RENAULT Abstract. We examine integer sequences G satisfying the Fibonacci recurrence relation 2 3 Gn = Gn−1 + Gn−2 that also have the property that G ≡ 1; a; a ; a ;::: (mod m) for some modulus m. We determine those moduli m for which these power Fibonacci sequences exist and the number of such sequences for a given m. We also provide formulas for the periods of these sequences, based on the period of the Fibonacci sequence F modulo m. Finally, we establish certain sequence/subsequence relationships between power Fibonacci sequences. 1. Introduction Let G be a bi-infinite integer sequence satisfying the recurrence relation Gn = Gn−1 +Gn−2. If G ≡ 1; a; a2; a3;::: (mod m) for some modulus m, then we will call G a power Fibonacci sequence modulo m. Example 1.1. Modulo m = 11, there are two power Fibonacci sequences: 1; 8; 9; 6; 4; 10; 3; 2; 5; 7; 1; 8 ::: and 1; 4; 5; 9; 3; 1; 4;::: Curiously, the second is a subsequence of the first. For modulo 5 there is only one such sequence (1; 3; 4; 2; 1; 3; :::), for modulo 10 there are no such sequences, and for modulo 209 there are four of these sequences. In the next section, Theorem 2.1 will demonstrate that 209 = 11·19 is the smallest modulus with more than two power Fibonacci sequences. In this note we will determine those moduli for which power Fibonacci sequences exist, and how many power Fibonacci sequences there are for a given modulus. -
Prime Divisors in the Rationality Condition for Odd Perfect Numbers
Aid#59330/Preprints/2019-09-10/www.mathjobs.org RFSC 04-01 Revised The Prime Divisors in the Rationality Condition for Odd Perfect Numbers Simon Davis Research Foundation of Southern California 8861 Villa La Jolla Drive #13595 La Jolla, CA 92037 Abstract. It is sufficient to prove that there is an excess of prime factors in the product of repunits with odd prime bases defined by the sum of divisors of the integer N = (4k + 4m+1 ℓ 2αi 1) i=1 qi to establish that there do not exist any odd integers with equality (4k+1)4m+2−1 between σ(N) and 2N. The existence of distinct prime divisors in the repunits 4k , 2α +1 Q q i −1 i , i = 1,...,ℓ, in σ(N) follows from a theorem on the primitive divisors of the Lucas qi−1 sequences and the square root of the product of 2(4k + 1), and the sequence of repunits will not be rational unless the primes are matched. Minimization of the number of prime divisors in σ(N) yields an infinite set of repunits of increasing magnitude or prime equations with no integer solutions. MSC: 11D61, 11K65 Keywords: prime divisors, rationality condition 1. Introduction While even perfect numbers were known to be given by 2p−1(2p − 1), for 2p − 1 prime, the universality of this result led to the the problem of characterizing any other possible types of perfect numbers. It was suggested initially by Descartes that it was not likely that odd integers could be perfect numbers [13]. After the work of de Bessy [3], Euler proved σ(N) that the condition = 2, where σ(N) = d|N d is the sum-of-divisors function, N d integer 4m+1 2α1 2αℓ restricted odd integers to have the form (4kP+ 1) q1 ...qℓ , with 4k + 1, q1,...,qℓ prime [18], and further, that there might exist no set of prime bases such that the perfect number condition was satisfied. -
Arxiv:1206.0407V3 [Math.NT] 22 Mar 2013 N Egto Utpehroi U.B Ovnin Eput We Convention, by Sum
NEW PROPERTIES OF MULTIPLE HARMONIC SUMS MODULO p AND p-ANALOGUES OF LESHCHINER’S SERIES KH. HESSAMI PILEHROOD, T. HESSAMI PILEHROOD, AND R. TAURASO Abstract. In this paper we present some new binomial identities for multiple harmonic sums whose indices are the sequences ({1}a, c, {1}b), ({2}a, c, {2}b) and prove a number of congruences for these sums modulo a prime p. The congruences obtained allow us to find nice p-analogues of Leshchiner’s series for zeta values and to refine a result due to M. Hoffman and J. Zhao about the set of generators of the multiple harmonic sums of weight 7 and 9 modulo p. ∗ As a further application we provide a new proof of Zagier’s formula for ζ ({2}a, 3, {2}b) based on a finite identity for partial sums of the zeta-star series. 1. Introduction In the last few years there has been a growing attention in the study of p-adic analogues of various binomial series related to multiple zeta values, which are nested generalizations of s s the classical Riemann zeta function ζ(s) = n=1 1/n . The main reason of interest of such p-analogues is that they are related to divisibility properties of multiple harmonic sums which can be considered as elementary “bricks” forP expressing complicated congruences. Before discussing this further we recall the precise definitions of such objects. ∗ r For r ∈ N, s = (s1,s2,...,sr) ∈ (Z ) , and a non-negative integer n, the alternating multiple harmonic sum is defined by r ki sgn (si) Hn(s1,s2,...,sr)= k|si| 1≤k1<kX2<...<kr≤n Yi=1 i and the “odd” alternating multiple harmonic sum is given by r sgn (s )ki H (s ,s ,...,s )= i . -
Motzkin Paths, Motzkin Polynomials and Recurrence Relations
Motzkin paths, Motzkin polynomials and recurrence relations Roy Oste and Joris Van der Jeugt Department of Applied Mathematics, Computer Science and Statistics Ghent University B-9000 Gent, Belgium [email protected], [email protected] Submitted: Oct 24, 2014; Accepted: Apr 4, 2015; Published: Apr 21, 2015 Mathematics Subject Classifications: 05A10, 05A15 Abstract We consider the Motzkin paths which are simple combinatorial objects appear- ing in many contexts. They are counted by the Motzkin numbers, related to the well known Catalan numbers. Associated with the Motzkin paths, we introduce the Motzkin polynomial, which is a multi-variable polynomial “counting” all Motzkin paths of a certain type. Motzkin polynomials (also called Jacobi-Rogers polyno- mials) have been studied before, but here we deduce some properties based on recurrence relations. The recurrence relations proved here also allow an efficient computation of the Motzkin polynomials. Finally, we show that the matrix en- tries of powers of an arbitrary tridiagonal matrix are essentially given by Motzkin polynomials, a property commonly known but usually stated without proof. 1 Introduction Catalan numbers and Motzkin numbers have a long history in combinatorics [19, 20]. 1 2n A lot of enumeration problems are counted by the Catalan numbers Cn = n+1 n , see e.g. [20]. Closely related to Catalan numbers are Motzkin numbers M , n ⌊n/2⌋ n M = C n 2k k Xk=0 similarly associated to many counting problems, see e.g. [9, 1, 18]. For example, the number of different ways of drawing non-intersecting chords between n points on a circle is counted by the Motzkin numbers. -
Input for Carnival of Math: Number 115, October 2014
Input for Carnival of Math: Number 115, October 2014 I visited Singapore in 1996 and the people were very kind to me. So I though this might be a little payback for their kindness. Good Luck. David Brooks The “Mathematical Association of America” (http://maanumberaday.blogspot.com/2009/11/115.html ) notes that: 115 = 5 x 23. 115 = 23 x (2 + 3). 115 has a unique representation as a sum of three squares: 3 2 + 5 2 + 9 2 = 115. 115 is the smallest three-digit integer, abc , such that ( abc )/( a*b*c) is prime : 115/5 = 23. STS-115 was a space shuttle mission to the International Space Station flown by the space shuttle Atlantis on Sept. 9, 2006. The “Online Encyclopedia of Integer Sequences” (http://www.oeis.org) notes that 115 is a tridecagonal (or 13-gonal) number. Also, 115 is the number of rooted trees with 8 vertices (or nodes). If you do a search for 115 on the OEIS website you will find out that there are 7,041 integer sequences that contain the number 115. The website “Positive Integers” (http://www.positiveintegers.org/115) notes that 115 is a palindromic and repdigit number when written in base 22 (5522). The website “Number Gossip” (http://www.numbergossip.com) notes that: 115 is the smallest three-digit integer, abc, such that (abc)/(a*b*c) is prime. It also notes that 115 is a composite, deficient, lucky, odd odious and square-free number. The website “Numbers Aplenty” (http://www.numbersaplenty.com/115) notes that: It has 4 divisors, whose sum is σ = 144. -
Square Series Generating Function Transformations 127
Journal of Inequalities and Special Functions ISSN: 2217-4303, URL: www.ilirias.com/jiasf Volume 8 Issue 2(2017), Pages 125-156. SQUARE SERIES GENERATING FUNCTION TRANSFORMATIONS MAXIE D. SCHMIDT Abstract. We construct new integral representations for transformations of the ordinary generating function for a sequence, hfni, into the form of a gen- erating function that enumerates the corresponding \square series" generating n2 function for the sequence, hq fni, at an initially fixed non-zero q 2 C. The new results proved in the article are given by integral{based transformations of ordinary generating function series expanded in terms of the Stirling num- bers of the second kind. We then employ known integral representations for the gamma and double factorial functions in the construction of these square series transformation integrals. The results proved in the article lead to new applications and integral representations for special function series, sequence generating functions, and other related applications. A summary Mathemat- ica notebook providing derivations of key results and applications to specific series is provided online as a supplemental reference to readers. 1. Notation and conventions Most of the notational conventions within the article are consistent with those employed in the references [11, 15]. Additional notation for special parameterized classes of the square series expansions studied in the article is defined in Table 1 on page 129. We utilize this notation for these generalized classes of square series functions throughout the article. The following list provides a description of the other primary notations and related conventions employed throughout the article specific to the handling of sequences and the coefficients of formal power series: I Sequences and Generating Functions: The notation hfni ≡ ff0; f1; f2;:::g is used to specify an infinite sequence over the natural numbers, n 2 N, where we define N = f0; 1; 2;:::g and Z+ = f1; 2; 3;:::g. -
Perfect Gaussian Integer Sequences of Arbitrary Length Soo-Chang Pei∗ and Kuo-Wei Chang† National Taiwan University∗ and Chunghwa Telecom†
Perfect Gaussian Integer Sequences of Arbitrary Length Soo-Chang Pei∗ and Kuo-Wei Chang† National Taiwan University∗ and Chunghwa Telecom† m Objectives N = p or N = p using Legendre N = pq where p and q are coprime Conclusion sequence and Gauss sum To construct perfect Gaussian integer sequences Simple zero padding method: We propose several methods to generate zero au- of arbitrary length N: Legendre symbol is defined as 1) Take a ZAC from p and q. tocorrelation sequences in Gaussian integer. If the 8 2 2) Interpolate q − 1 and p − 1 zeros to these signals sequence length is prime number, we can use Leg- • Perfect sequences are sequences with zero > 1, if ∃x, x ≡ n(mod N) n ! > autocorrelation. = < 0, n ≡ 0(mod N) to get two signals of length N. endre symbol and provide more degree of freedom N > 3) Convolution these two signals, then we get a than Yang’s method. If the sequence is composite, • Gaussian integer is a number in the form :> −1, otherwise. ZAC. we develop a general method to construct ZAC se- a + bi where a and b are integer. And the Gauss sum is defined as N−1 ! Using the idea of prime-factor algorithm: quences. Zero padding is one of the special cases of • A Perfect Gaussian sequence is a perfect X n −2πikn/N G(k) = e Recall that DFT of size N = N1N2 can be done by this method, and it is very easy to implement. sequence that each value in the sequence is a n=0 N taking DFT of size N1 and N2 seperately[14]. -
Motzkin Paths
Discrete Math. 312 (2012), no. 11, 1918-1922 Noncrossing Linked Partitions and Large (3; 2)-Motzkin Paths William Y.C. Chen1, Carol J. Wang2 1Center for Combinatorics, LPMC-TJKLC Nankai University, Tianjin 300071, P.R. China 2Department of Mathematics Beijing Technology and Business University Beijing 100048, P.R. China emails: [email protected], wang [email protected] Abstract. Noncrossing linked partitions arise in the study of certain transforms in free probability theory. We explore the connection between noncrossing linked partitions and (3; 2)-Motzkin paths, where a (3; 2)-Motzkin path can be viewed as a Motzkin path for which there are three types of horizontal steps and two types of down steps. A large (3; 2)-Motzkin path is a (3; 2)-Motzkin path for which there are only two types of horizontal steps on the x-axis. We establish a one-to-one correspondence between the set of noncrossing linked partitions of f1; : : : ; n + 1g and the set of large (3; 2)- Motzkin paths of length n, which leads to a simple explanation of the well-known relation between the large and the little Schr¨odernumbers. Keywords: Noncrossing linked partition, Schr¨oderpath, large (3; 2)-Motzkin path, Schr¨odernumber AMS Classifications: 05A15, 05A18. 1 1 Introduction The notion of noncrossing linked partitions was introduced by Dykema [5] in the study of the unsymmetrized T-transform in free probability theory. Let [n] denote f1; : : : ; ng. It has been shown that the generating function of the number of noncrossing linked partitions of [n + 1] is given by 1 p X 1 − x − 1 − 6x + x2 F (x) = f xn = : (1.1) n+1 2x n=0 This implies that the number of noncrossing linked partitions of [n + 1] is equal to the n-th large Schr¨odernumber Sn, that is, the number of large Schr¨oderpaths of length 2n. -
Convolution on the N-Sphere with Application to PDF Modeling Ivan Dokmanic´, Student Member, IEEE, and Davor Petrinovic´, Member, IEEE
IEEE TRANSACTIONS ON SIGNAL PROCESSING, VOL. 58, NO. 3, MARCH 2010 1157 Convolution on the n-Sphere With Application to PDF Modeling Ivan Dokmanic´, Student Member, IEEE, and Davor Petrinovic´, Member, IEEE Abstract—In this paper, we derive an explicit form of the convo- emphasis on wavelet transform in [8]–[12]. Computation of the lution theorem for functions on an -sphere. Our motivation comes Fourier transform and convolution on groups is studied within from the design of a probability density estimator for -dimen- the theory of noncommutative harmonic analysis. Examples sional random vectors. We propose a probability density function (pdf) estimation method that uses the derived convolution result of applications of noncommutative harmonic analysis in engi- on . Random samples are mapped onto the -sphere and esti- neering are analysis of the motion of a rigid body, workspace mation is performed in the new domain by convolving the samples generation in robotics, template matching in image processing, with the smoothing kernel density. The convolution is carried out tomography, etc. A comprehensive list with accompanying in the spectral domain. Samples are mapped between the -sphere theory and explanations is given in [13]. and the -dimensional Euclidean space by the generalized stereo- graphic projection. We apply the proposed model to several syn- Statistics of random vectors whose realizations are observed thetic and real-world data sets and discuss the results. along manifolds embedded in Euclidean spaces are commonly termed directional statistics. An excellent review may be found Index Terms—Convolution, density estimation, hypersphere, hy- perspherical harmonics, -sphere, rotations, spherical harmonics. in [14]. It is of interest to develop tools for the directional sta- tistics in analogy with the ordinary Euclidean. -
And Its Properties on the Sequence Related to Lucas Numbers
Mathematica Aeterna, Vol. 2, 2012, no. 1, 63 - 75 On the sequence related to Lucas numbers and its properties Cennet Bolat Department of Mathematics, Art and Science Faculty, Mustafa Kemal University, 31034, Hatay,Turkey Ahmet I˙pek Department of Mathematics, Art and Science Faculty, Mustafa Kemal University, 31034, Hatay,Turkey Hasan Köse Department of Mathematics, Science Faculty, Selcuk University 42031, Konya,Turkey Abstract The Fibonacci sequence has been generalized in many ways, some by preserving the initial conditions, and others by preserving the recur- rence relation. In this article, we study a new generalization {Lk,n}, with initial conditions Lk,0 = 2 and Lk,1 = 1, which is generated by the recurrence relation Lk,n = kLk,n−1 + Lk,n−2 for n ≥ 2, where k is integer number. Some well-known sequence are special case of this generalization. The Lucas sequence is a special case of {Lk,n} with k = 1. Modified Pell-Lucas sequence is {Lk,n} with k = 2. We produce an extended Binet’s formula for {Lk,n} and, thereby, identities such as Cassini’s, Catalan’s, d’Ocagne’s, etc. using matrix algebra. Moreover, we present sum formulas concerning this new generalization. Mathematics Subject Classi…cation: 11B39, 15A23. Keywords: Classic Fibonacci numbers; Classic Lucas numbers; k-Fibonacci numbers; k-Lucas numbers, Matrix algebra. 64 C. Bolat, A. Ipek and H. Kose 1 Introduction In recent years, many interesting properties of classic Fibonacci numbers, clas- sic Lucas numbers and their generalizations have been shown by researchers and applied to almost every …eld of science and art. -
Impartial Games
Combinatorial Games MSRI Publications Volume 29, 1995 Impartial Games RICHARD K. GUY In memory of Jack Kenyon, 1935-08-26 to 1994-09-19 Abstract. We give examples and some general results about impartial games, those in which both players are allowed the same moves at any given time. 1. Introduction We continue our introduction to combinatorial games with a survey of im- partial games. Most of this material can also be found in WW [Berlekamp et al. 1982], particularly pp. 81{116, and in ONAG [Conway 1976], particu- larly pp. 112{130. An elementary introduction is given in [Guy 1989]; see also [Fraenkel 1996], pp. ??{?? in this volume. An impartial game is one in which the set of Left options is the same as the set of Right options. We've noticed in the preceding article the impartial games = 0=0; 0 0 = 1= and 0; 0; = 2: {|} ∗ { | } ∗ ∗ { ∗| ∗} ∗ that were born on days 0, 1, and 2, respectively, so it should come as no surprise that on day n the game n = 0; 1; 2;:::; (n 1) 0; 1; 2;:::; (n 1) ∗ {∗ ∗ ∗ ∗ − |∗ ∗ ∗ ∗ − } is born. In fact any game of the type a; b; c;::: a; b; c;::: {∗ ∗ ∗ |∗ ∗ ∗ } has value m,wherem =mex a;b;c;::: , the least nonnegative integer not in ∗ { } the set a;b;c;::: . To see this, notice that any option, a say, for which a>m, { } ∗ This is a slightly revised reprint of the article of the same name that appeared in Combi- natorial Games, Proceedings of Symposia in Applied Mathematics, Vol. 43, 1991. Permission for use courtesy of the American Mathematical Society.