In mathematics, the Eisenstein integers, occasionally also known as Eulerian integers, are the complex numbers of the form z = a + b ω, {\displaystyle z=a+b\omega,} where a and b are integers and ω = − 1 + i 3 2 = e i 2 π / 3 {\displaystyle \omega ={\frac {-1+i{\sqrt {3}}}{2}}=e^{i2\pi /3}} is a primitive cube root of unity. Wikipedia