Polymorph
An integer which is expressible in more than one way in the form x^2+Dy^2 or x^2-Dy^2 where x^2 is relatively prime to Dy^2. If the integer is expressible in only one way, it is called a monomorph.
See also
Antimorph, Demiregular Tessellation, Idoneal Number, Monomorph, Pell EquationExplore with Wolfram|Alpha
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Cite this as:
Weisstein, Eric W. "Polymorph." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/Polymorph.html