5 note that the only primes not of the form 6n ± 1 6 n ± 1 are 2 2 and 3 3. Prove there are infinitely many primes of the form 6n − 1 6 n 1 with the following: A number of the form 6n + 5 6 n + 5 is not divisible by 2 2 or 3 3.
Now your sum becomes $$\sum_ {1\leq k\leq 2025}k^ {6n}\mod 7=\sum_ {1\leq k\leq 2025,\,7\nmid k}1\mod 7$$ to calculuate. By eliminating $5$ as per the condition, the next possible factors are $7$, $11$ and $13$. I was stuck on a problem from mathematical circles:
Prove that the number $6n^3 + 3$ cannot be a perfect sixth power of an. If you're talking about euler's 6n + 1 6 n + 1 theorem, what that says is that any prime of the form 6n + 1 6 n +. In another post, show that every prime p>3 is either of the form 6n+1 or of the form 6n+5, it was shown that primes are in the form $ (6n+1)$ or $ (6n+5)$. And does it cover all primes?
At least for numbers less than $10^9$. This is because when we divide an integer m m. (i) prove that the product of two numbers of the form 6n + 1 6 n + 1 is also of that form. Every integer is of the form 6n 6 n or 6n + 1 6 n + 1 or 6n + 2 6 n + 2 or 6n + 3 6 n + 3 or 6n + 4 6 n + 4 or 6n + 5 6 n + 5 for some integer n n.
Russian experience, which reads as follows: