On prime divisors of Mersenne numbers
On prime factors of sums of integers I
On prime factors of sums of integers III
On prime values of reducible quadratic polynomials
It is shown that Dickson’s Conjecture about primes in linear polynomials implies that if f is a reducible quadratic polynomial with integral coefficients and non-zero discriminant then for every r there exists an integer such that the polynomial represents at least r distinct primes.
On prime-detecting sequences from Apéry's recurrence formulae for and .
On Rowland's sequence.
On square values of the product of the Euler totient and sum of divisors functions
If n is a positive integer such that ϕ(n)σ(n) = m² for some positive integer m, then m ≤ n. We put m = n-a and we study the positive integers a arising in this way.
On the complexity of testing elite primes.
On the converse of Wolstenholme's Theorem
On the exact number of primes in the arithmetic progression 4n ... 1 and 6n ... 1.
On the Fermat periods of natural numbers.
On the greatest prime factor of
On the greatest prime factors of polynomials at integer points
On the -th extension of the sieve of Eratosthenes.
On the largest prime factors of n and n+1.
On the largest prime factors of n and n+1. (Short Communication).
On the number of prime divisors of a binomial coefficient.
On the quartic character of quadratic units.
On the set of values of the Euler function.
On the subsequence of primes having prime subscripts.