Editing Concatenation (section)

===Recreational mathematics===
In [[recreational mathematics]], many problems concern the properties of numbers under concatenation of their numerals in some [[radix|base]].  Examples include [[home prime]]s (primes obtained by repeatedly factoring the increasing concatenation of prime factors of a given number), [[Smarandache–Wellin number]]s (the concatenations of the first [[prime number]]s), and the [[Champernowne constant|Champernowne]] and [[Copeland–Erdős constant]]s (the real numbers formed by the decimal representations of the [[positive integers]] and the prime numbers, respectively).