Prime Numbers

"``Prime hunting" can be considered as a research area of computational number theory. Its goal is to find special combinations of integers and prove their primality. Four research groups, established by A. Járai between 1992 and 2014, published numerous world class scientific results. In this period, due to Járai's arithmetic routines fastest in the world, they reached the world record 19 times, namely found the largest known twin primes 9 times, Sophie Germain primes 7 times, a prime of the form n^4+1, a number which is simultaneously twin and Sophie Germain prime and the three largest known primes forming a Cunningham chain of length 3 of the first kind. When A. Járai retired, the investigations of this area were suspended. In the beginning of 2020 the research was reopened by G. Farkas at the newly-founded campus (Szombathely) of ELTE. The first signal success came in the end of May 2020. They proved the primality of the numbers which form the largest known Cunningham chains of length 2 of the 2nd kind. In this paper we report on a newly started prime hunting project with the aim of increasing our students' research activity.

On a New Formula for Fibonacci’s Family m-step Numbers and Some Applications

In this work, we obtain a new formula for Fibonacci’s family m-step sequences. We use our formula to find the nth term with less time complexity than the matrix multiplication method. Then, we extend our results for all linear homogeneous recurrence m-step relations with constant coefficients by using the last few terms of its corresponding Fibonacci’s family m-step sequence. As a computational number theory application, we develop a method to estimate the square roots.