Catalan's Problem
The problem of finding the number of different ways in which a Product of 
different ordered Factors canbe calculated by pairs (i.e., the number of Binary Bracketings of letters). For example, forthe four Factors 
, 
, 
, and 
, there are five possibilities: 
, 
, 
,
, and 
. The solution was given by Catalan in 1838 as
and is equal to the Catalan Number
.See also Binary Bracketing, Catalan's Diophantine Problem, Euler's Polygon Division Problem
References
Dörrie, H. 100 Great Problems of Elementary Mathematics: Their History and Solutions. New York: Dover, p. 23, 1965.
- Ulam Map
- Ulam Number
- Ulam Sequence
- Ulam's Problem
- Ultrametric
- Ultraradical
- Ultraspherical Differential Equation
- Ultraspherical Function
- Ultraspherical Polynomial
- Umbilic Point
- Umbral Calculus
- Umbrella
- Unambiguous
- Unbiased
- Uncia
- Uncorrelated
- Uncountable Set
- Uncountably Infinite Set
- Undecagon
- Undecidable
- Undecillion
- Undetermined Coefficients Method
- Undulating Number
- Unduloid
- Unexpected Hanging Paradox