need second opinion

[David W. Wilson]

Michael Somos wrote:

> I believe that it was proven by Jacobi using theta functions that every
> positive integer is the sum of four squares. That is the reason for the
> appearance of n^2+1 for four dimensions. Any dimension greater than four
> would give the same result. The results for less than four are not so
> simple. Shalom, Michael

Simple enough for dimension 1.