Problem B. 4707. (April 2015)

B. 4707. Let \(\displaystyle t>1\) be an odd integer. Prove that there exist only a finite number of pairs of integers \(\displaystyle n\) and \(\displaystyle k\), not smaller than \(\displaystyle t\) such that \(\displaystyle S=\binom{n}{t} + \binom{k}{t}\) is a prime.

Suggested by B. Maga, Budapest

(5 pont)

Deadline expired on May 11, 2015.

Statistics:

13 students sent a solution.
5 points:	Baran Zsuzsanna, Glasznova Maja, Schwarcz Tamás, Williams Kada.
4 points:	Gáspár Attila, Imolay András, Nagy-György Pál, Németh 123 Balázs, Schrettner Bálint, Szebellédi Márton, Wiandt Péter.
0 point:	2 students.

Problems in Mathematics of KöMaL, April 2015