23-Jul-1995

Unsolved Problem 30:

Is every integer the sum of four cubes?

Here we allow the cubes to be positive, negative, or zero. For example, 84=0^3+41639611^3+(-41531726)^3+(-8241191)^3. It is not known if 148, for example, is the sum of four cubes.

Reference:

[Guy 1994]
Richard K. Guy, Unsolved Problems in Number Theory, second edition. Springer Verlag. New York: 1994. Page 151.
Sum of Four Cubes
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