MathDB
Problems
Contests
National and Regional Contests
Moldova Contests
Moldova Team Selection Test
1999 Moldova Team Selection Test
8
Find an f such that f(f(n))=n^2 [Romania 1978]
Find an f such that f(f(n))=n^2 [Romania 1978]
Source: Romania 1978
July 20, 2009
algebra proposed
algebra
Problem Statement
Find a function
f
:
N
ā
N
f: \mathbb N \to \mathbb N
f
:
N
ā
N
such that for all positive integers
n
n
n
, f(f(n))\equal{}n^2.
Back to Problems
View on AoPS