Dr. H. Stephan (WIAS Berlin)
Thursday, May 3, 2018 - 14:00
Weierstraß-Institut
Mohrenstr. 39, 10117 Berlin, Erhard-Schmidt-Hörsaal, Erdgeschoss
Seminar Numerische Mathematik
Pseudoprimes are integers that are no primes but behave like them in some sense. Suppose we have a theorem like the following: If n is a prime, then statement A(n) holds. In general, the opposite is not true: It may be that A(n) holds, but n is a composite number, a so-called pseudo prime with respect to statement A. Pseudoprimes are interesting if they are very rare, as for instance Perrin's pseudoprimes, the smallest of which is 271441. The talk introduces pseudoprimes which are based on recurrent sequences. In addition, some new numerical results on Perrin's pseudoprimes and a fast algorithm for their calculation are presented.
submitted by lawrenz (marion.lawrenz@wias-berlin.de, 030 20372566)