Find all $a$, so $q$ prime number which ,$q\times n= aaaaaaa$
75685
Prove that there is prime number and natural so $n\times q$ digits are $1$.
40156
Determine all primes $p$ for which $5$ is a quadratic residue modulo $p$
45700
How can I know if $2^{2^{2^{2^{2}}}}+1=?$ is prime?
126945
checking if a number is a prime
5978
Prove that there exists only one prime number of the form $p^2−1$ where $p≥2$ is an integer
30134
For $a,n \in \Bbb N$, how to prove if $a^n-1$ is prime then $a=2$ and $n$ is prime?
124869
Prime factor of $A=14^7+14^2+1$
4402
Group of order $pqr$, $p < q < r$ primes
78342
When is $\phi(n)$ a prime number?
66851
If $p,q$ are primes $(pq,a)=1$ and $p-1|q-1$ then prove $a^{q-1}\equiv 1\pmod{pq}$
92737
primes whose difference is a multiple of $n$
118383
If $n = 51! +1$, then find number of primes among $n+1,n+2,\ldots, n+50$
151036
arithmetic progression of primes
144814
If $p$ and $q$ are primes, which binomial coefficients $\binom{pq}{n}$ are divisible by $pq$?
144622
Proof: If no prime less than or equal to $\sqrt{n}$ divides $n$, then $n$ is a prime
142904
finding the running time for my algorithm for finding whether an input is prime in terms of the input
75206
If $a$, $a+2$ and $a+4$ are prime numbers then, how can one prove that there is only one solution for $a$?