## 'Producing an Integer' printed from http://nrich.maths.org/

When is the value of the product $$\left(1 + {1 \over 2}\right)\left(1 + {1 \over 3}\right)\left(1 + {1 \over 4}\right)...\left(1 + {1 \over n}\right)$$ equal to an integer?