Poznámka o číslech sudých
We describe a simple procedure to find Aurifeuillian factors of values of cyclotomic polynomials for integers and . Assuming a suitable Riemann Hypothesis, the algorithm runs in deterministic time , using space, where .
We extend Hoggar's theorem that the sum of two independent discrete-valued log-concave random variables is itself log-concave. We introduce conditions under which the result still holds for dependent variables. We argue that these conditions are natural by giving some applications. Firstly, we use our main theorem to give simple proofs of the log-concavity of the Stirling numbers of the second kind and of the Eulerian numbers. Secondly, we prove results concerning the log-concavity of the sum of...