It is impossible for any number which is a power greater than the second to be written as a sum of two like powers. I have a truly marvelous demonstration of this proposition which this margin is too narrow to contain.
Pierre de FermatAnd perhaps, posterity will thank me for having shown that the ancients did not know everything.
Pierre de FermatTo divide a cube into two other cubes, a fourth power, or in general any power whatever into two powers of the same denomination above the second is impossible, and I have assuredly found an admirable proof of this, but the margin is too narrow to contain it.
Pierre de Fermat