My first problem
Number Theory
Level
3
\[ \large{T_m=\underbrace{17^{17^{\cdot^{\cdot^{\cdot^{17}}}}}}_{m \text{ times}}} \]
Find the smallest possible value of \(n\) such that the numbers \(T_n,T_{n+1},T_{n+2},\ldots\) all have the same last (rightmost) 2017 digits.
Bonus: Generalize to the last \(k\) digits.
by
Marco Brezzi