Delving Deeper: The Ubiquitous Catalan Numbers

2006 ◽  
Vol 100 (3) ◽  
pp. 184-188
Author(s):  
Thomas Koshy

Just as Fibonacci and Lucas numbers are a great source of fun and excitement for both amateurs and professionals alike (Askey 2005, Koshy 2002), so are the less well-known Catalan numbers. They too are excellent candidates for mathematical activities such as experimentation, exploration, and conjecture. I was surprised to see that, like Fibonacci and Lucas numbers, Catalan numbers seemed to show up in several problems I had assigned to students over the years.

2011 ◽  
Vol 5 (2) ◽  
pp. 176-200 ◽  
Author(s):  
Emanuele Munarini

We obtain a general identity involving the row-sums of a Riordan matrix and the harmonic numbers. From this identity, we deduce several particular identities involving numbers of combinatorial interest, such as generalized Fibonacci and Lucas numbers, Catalan numbers, binomial and trinomial coefficients, Stirling numbers. 2000 Mathematics Subject Classification: Primary: 05A15; Secondary: 05A10.


2020 ◽  
Vol 70 (3) ◽  
pp. 641-656
Author(s):  
Amira Khelifa ◽  
Yacine Halim ◽  
Abderrahmane Bouchair ◽  
Massaoud Berkal

AbstractIn this paper we give some theoretical explanations related to the representation for the general solution of the system of the higher-order rational difference equations$$\begin{array}{} \displaystyle x_{n+1} = \dfrac{1+2y_{n-k}}{3+y_{n-k}},\qquad y_{n+1} = \dfrac{1+2z_{n-k}}{3+z_{n-k}},\qquad z_{n+1} = \dfrac{1+2x_{n-k}}{3+x_{n-k}}, \end{array}$$where n, k∈ ℕ0, the initial values x−k, x−k+1, …, x0, y−k, y−k+1, …, y0, z−k, z−k+1, …, z1 and z0 are arbitrary real numbers do not equal −3. This system can be solved in a closed-form and we will see that the solutions are expressed using the famous Fibonacci and Lucas numbers.


1989 ◽  
Vol 03 (14) ◽  
pp. 1071-1085 ◽  
Author(s):  
L. A. BURSILL ◽  
GEORGE RYAN ◽  
XUDONG FAN ◽  
J. L. ROUSE ◽  
JULIN PENG ◽  
...  

Observations of the sunflower Helianthus tuberosus reveal the occurrence of both Fibonacci and Lucas numbers of visible spirals (parastichies). This species is multi-headed, allowing a quantitative study of the relative abundance of these two types of phyllotaxis. The florets follow a spiral arrangement. It is remarkable that the Lucas series occurred, almost invariably, in the first-flowering heads of individual plants. The occurrence of left-and right-handed chirality was found to be random, within experimental error, using an appropriate chirality convention. Quantitative crystallographic studies allow the average growth law to be derived (r = alτ−1; θ = 2πl/(τ + 1), where a is a constant, l is the seed cell number and τ is the golden mean [Formula: see text]). They also reveal departures from classical theoretical models of phyllotaxis, taking the form of persistent oscillations in both divergence angle and radius. The experimental results are discussed in terms of a new theoretical model for the close-packing of growing discs. Finally, a basis for synthesis of (inorganic) spiral lattice structures is proposed.


2016 ◽  
Vol 66 (3) ◽  
Author(s):  
Emrah Kiliç ◽  
Helmut Prodinger

AbstractWe give a systematic approach to compute certain sums of squares of Fibonomial coefficients with finite products of generalized Fibonacci and Lucas numbers as coefficients. The technique is to rewrite everything in terms of a variable


2020 ◽  
Vol 26 (3) ◽  
pp. 189-202
Author(s):  
K. M. Nagaraja ◽  
◽  
P. Dhanya ◽  

2015 ◽  
Vol 168 (2) ◽  
pp. 161-186
Author(s):  
Hajime Kaneko ◽  
Takeshi Kurosawa ◽  
Yohei Tachiya ◽  
Taka-aki Tanaka

Sign in / Sign up

Export Citation Format

Share Document