In some areas of our country, there are odd and even numbers for the purchase quantity of chairs.
Our local area has this kind of emphasis. The chairs we buy here must be in an odd number, that is, an odd number, but the tables can be placed in an even number. That is to say, an extra chair is provided to prevent the chair from being damaged again in the future and can be used in time. But later I learned that buying an even number of chairs is unlucky, and may even affect the good or bad luck of your family. So most of the chairs are purchased in odd numbers.