Nice polynomials are polynomials whose coefficients, roots, and critical points are integers. The earliest papers on nice polynomials [1, 2, 3] give an explicit formula for all nice cubics. All the derivations of this formula use Pythagorean triples.
In 1999 the problem of finding, constructing, and classifying nice polynomials was added to the list of unsolved problems  in The American Mathematical Monthly. Other papers soon followed, including  and , with extending the results of nice polynomials to polynomials with coefficients, roots, and critical points in integral domains D. Such polynomials are called D-nice.