There is given sequence $$a_{1},a_{2},a_{3},...$$ Where $a_{n}\in\{1,2,...,N\}$ for every natural $n$.
It is also known that this sequence is periodic.
Find the fundamental period the sequence.
I know that "Discrete Fourier Transform" is usefull. But to apply it to extract "$T$" from equation $a_{n+T}=a_{n}$ ?
Regards.