  Let $F$ be a binary form with integer coefficients, non-zero discriminant and
degree $d \geq 3$. Let $R_F(Z)$ denote the number of integers of absolute value
at most $Z$ which are represented by $F$. In 2019 Stewart and Xiao proved that
$R_F(Z) \sim C_FZ^{2/d}$ for some positive number $C_F$. We compute $C_{R_n}$
and $C_{J_n}$ for the binary forms $R_n(x, y)$ and $J_n(x, y)$ defined by means
of the relation $ (x + yi)^n = R_n(x, y) + J_n(x, y)i$, where the variables $x$
and $y$ are real.
