3 [ Examples and counterexamples. Constructions ]

Is it true that all numbers of the form $p_{1} p_{2} \ldots p_{n}+1$ are prime? ( $p_{k}-k$-th prime number.)
$2 \cdot 3 \cdot 5 \cdot 7 \cdot 11 \cdot 13+1=30031=59 \cdot 509$

## Answer

Incorrect.

## Problem