An Eisenstein integer is a complex number of the form a+bω, where ω is one of the roots of unity,
ω = (-1/2 + i sqrt(3)/2),
and a,b are integers.
Eisenstein integers are members of the imaginary quadratic field Q(sqrt(-3))
Eisenstein integers form a ring, denoted Z[ω]
Eisenstein integers can be uniquely factored in terms of other Eisenstein integers (known as Eisenstein primes) up to powers of its units and rearrangements.
The units of Z[ω] are ±1, ±ω, and ±ω².
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Wikipedia: Eisenstein integer
Mathworld: Eisenstein Integer
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