Magic Squares

The story goes that about 4200 years ago in a place of China, Emperor Yu had decided to make some offerings to the gods to fulfill their anger.
The story was that the river had overflowed it, causing great destruction and great loss of life among his subjects.
Thus, in order to cushion the divine fury, the emperor offered to the Gods 3 animals.
The altar was near the river, and out came a sacred tortoise, approached the 3 animals killed and returned to the river. It was clear that the gods were not pleased with the offering. So did the Emperor Yu sacrifice another animal.
The turtle came out, but also retired.
What number of animals please the gods?.
Had between the pages of very clever young emperor, who said he saw the shell of the turtle about signs and numbers (How accounts or grouped points).
Immediately wrote on the ground and could see the following drawing:

Which equals the numerical arrangement:

Located opposite the Emperor Yu, the drawing could read like this:

It was amazing! The first nine numbers of the world, together in any direction, vertical, horizontal and diagonal.
They numbered 15!
They learned that the number of animals to be sacrificed to the gods was 15.
This is the story told to explain that magic squares have sacred origin. It is not really just a numbers game, but the result is certainly surprising.
The Chinese magic square, the first few are known, called Lo Shu (The Book of the Lo River), and has other important properties.
For example, in the four corners are even numbers (Yin), and odd numbers (Yang) form a central cross. The number 5, which is at the center, symbolizing the Earth, and the five elements of oriental universe (water, fire, wood, metal and earth).
The numerical symbolism of the five elements also is disposed around the number five.